servoshell: Enable accesskit integration. (#37519)

These changes ensure that our browser shell can integrate with
screenreaders. We do not provide any accessibility information about
webview content yet, which requires further API design work in both
Servo, accesskit, and egui.

Testing: No a11y-specific testing at this point; just verifying that
existing tests continue to pass.
Fixes: part of #4344

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

Cargo.lock

@@ -18,6 +18,98 @@ version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c71b1793ee61086797f5c80b6efa2b8ffa6d5dd703f118545808a7f2e27f7046"
 
+[[package]]
+name = "accesskit"
+version = "0.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3d3b8f9bae46a948369bc4a03e815d4ed6d616bd00de4051133a5019dc31c5a"
+
+[[package]]
+name = "accesskit_atspi_common"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c5dd55e6e94949498698daf4d48fb5659e824d7abec0d394089656ceaf99d4f"
+dependencies = [
+ "accesskit",
+ "accesskit_consumer",
+ "atspi-common",
+ "serde",
+ "thiserror 1.0.69",
+ "zvariant",
+]
+
+[[package]]
+name = "accesskit_consumer"
+version = "0.26.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f47983a1084940ba9a39c077a8c63e55c619388be5476ac04c804cfbd1e63459"
+dependencies = [
+ "accesskit",
+ "hashbrown",
+ "immutable-chunkmap",
+]
+
+[[package]]
+name = "accesskit_macos"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7329821f3bd1101e03a7d2e03bd339e3ac0dc64c70b4c9f9ae1949e3ba8dece1"
+dependencies = [
+ "accesskit",
+ "accesskit_consumer",
+ "hashbrown",
+ "objc2 0.5.2",
+ "objc2-app-kit 0.2.2",
+ "objc2-foundation 0.2.2",
+]
+
+[[package]]
+name = "accesskit_unix"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcee751cc20d88678c33edaf9c07e8b693cd02819fe89053776f5313492273f5"
+dependencies = [
+ "accesskit",
+ "accesskit_atspi_common",
+ "async-channel",
+ "async-executor",
+ "async-task",
+ "atspi",
+ "futures-lite",
+ "futures-util",
+ "serde",
+ "zbus",
+]
+
+[[package]]
+name = "accesskit_windows"
+version = "0.24.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24fcd5d23d70670992b823e735e859374d694a3d12bfd8dd32bd3bd8bedb5d81"
+dependencies = [
+ "accesskit",
+ "accesskit_consumer",
+ "hashbrown",
+ "paste",
+ "static_assertions",
+ "windows 0.58.0",
+ "windows-core 0.58.0",
+]
+
+[[package]]
+name = "accesskit_winit"
+version = "0.23.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6a48dad5530b6deb9fc7a52cc6c3bf72cdd9eb8157ac9d32d69f2427a5e879"
+dependencies = [
+ "accesskit",
+ "accesskit_macos",
+ "accesskit_unix",
+ "accesskit_windows",
+ "raw-window-handle",
+ "winit",
+]
+
 [[package]]
 name = "accountable-refcell"
 version = "0.2.2"
@@ -328,6 +420,30 @@ dependencies = [
  "libloading",
 ]
 
+[[package]]
+name = "async-broadcast"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "435a87a52755b8f27fcf321ac4f04b2802e337c8c4872923137471ec39c37532"
+dependencies = [
+ "event-listener",
+ "event-listener-strategy",
+ "futures-core",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "async-channel"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89b47800b0be77592da0afd425cc03468052844aff33b84e33cc696f64e77b6a"
+dependencies = [
+ "concurrent-queue",
+ "event-listener-strategy",
+ "futures-core",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "async-compression"
 version = "0.4.25"
@@ -342,6 +458,80 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "async-executor"
+version = "1.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb812ffb58524bdd10860d7d974e2f01cc0950c2438a74ee5ec2e2280c6c4ffa"
+dependencies = [
+ "async-task",
+ "concurrent-queue",
+ "fastrand",
+ "futures-lite",
+ "pin-project-lite",
+ "slab",
+]
+
+[[package]]
+name = "async-fs"
+version = "2.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebcd09b382f40fcd159c2d695175b2ae620ffa5f3bd6f664131efff4e8b9e04a"
+dependencies = [
+ "async-lock",
+ "blocking",
+ "futures-lite",
+]
+
+[[package]]
+name = "async-io"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1237c0ae75a0f3765f58910ff9cdd0a12eeb39ab2f4c7de23262f337f0aacbb3"
+dependencies = [
+ "async-lock",
+ "cfg-if",
+ "concurrent-queue",
+ "futures-io",
+ "futures-lite",
+ "parking",
+ "polling",
+ "rustix 1.0.7",
+ "slab",
+ "tracing",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "async-lock"
+version = "3.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff6e472cdea888a4bd64f342f09b3f50e1886d32afe8df3d663c01140b811b18"
+dependencies = [
+ "event-listener",
+ "event-listener-strategy",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "async-process"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cde3f4e40e6021d7acffc90095cbd6dc54cb593903d1de5832f435eb274b85dc"
+dependencies = [
+ "async-channel",
+ "async-io",
+ "async-lock",
+ "async-signal",
+ "async-task",
+ "blocking",
+ "cfg-if",
+ "event-listener",
+ "futures-lite",
+ "rustix 1.0.7",
+ "tracing",
+]
+
 [[package]]
 name = "async-recursion"
 version = "1.1.1"
@@ -353,6 +543,41 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "async-signal"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7605a4e50d4b06df3898d5a70bf5fde51ed9059b0434b73105193bc27acce0d"
+dependencies = [
+ "async-io",
+ "async-lock",
+ "atomic-waker",
+ "cfg-if",
+ "futures-core",
+ "futures-io",
+ "rustix 1.0.7",
+ "signal-hook-registry",
+ "slab",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "async-task"
+version = "4.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b75356056920673b02621b35afd0f7dda9306d03c79a30f5c56c44cf256e3de"
+
+[[package]]
+name = "async-trait"
+version = "0.1.88"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e539d3fca749fcee5236ab05e93a52867dd549cc157c8cb7f99595f3cedffdb5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "async-tungstenite"
 version = "0.29.1"
@@ -385,6 +610,57 @@ version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41e67cd8309bbd06cd603a9e693a784ac2e5d1e955f11286e355089fcab3047c"
 
+[[package]]
+name = "atspi"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be534b16650e35237bb1ed189ba2aab86ce65e88cc84c66f4935ba38575cecbf"
+dependencies = [
+ "atspi-common",
+ "atspi-connection",
+ "atspi-proxies",
+]
+
+[[package]]
+name = "atspi-common"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1909ed2dc01d0a17505d89311d192518507e8a056a48148e3598fef5e7bb6ba7"
+dependencies = [
+ "enumflags2",
+ "serde",
+ "static_assertions",
+ "zbus",
+ "zbus-lockstep",
+ "zbus-lockstep-macros",
+ "zbus_names",
+ "zvariant",
+]
+
+[[package]]
+name = "atspi-connection"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "430c5960624a4baaa511c9c0fcc2218e3b58f5dbcc47e6190cafee344b873333"
+dependencies = [
+ "atspi-common",
+ "atspi-proxies",
+ "futures-lite",
+ "zbus",
+]
+
+[[package]]
+name = "atspi-proxies"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5e6c5de3e524cf967569722446bcd458d5032348554d9a17d7d72b041ab7496"
+dependencies = [
+ "atspi-common",
+ "serde",
+ "zbus",
+ "zvariant",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.5.0"
@@ -604,6 +880,19 @@ dependencies = [
  "objc2 0.5.2",
 ]
 
+[[package]]
+name = "blocking"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "703f41c54fc768e63e091340b424302bb1c29ef4aa0c7f10fe849dfb114d29ea"
+dependencies = [
+ "async-channel",
+ "async-task",
+ "futures-io",
+ "futures-lite",
+ "piper",
+]
+
 [[package]]
 name = "bluetooth"
 version = "0.0.1"
@@ -654,7 +943,7 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c150fd617830fd121919bbd500a784507e8af1bae744efcf587591c65c375d4"
 dependencies = [
- "hex",
+ "hex 0.3.2",
 ]
 
 [[package]]
@@ -664,7 +953,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6dae8337ff67fe8ead29a28a0115605753e6a5205d4b6017e9f42f198c3c50a"
 dependencies = [
  "dbus",
- "hex",
+ "hex 0.3.2",
 ]
 
 [[package]]
@@ -768,7 +1057,7 @@ dependencies = [
  "bitflags 2.9.1",
  "log",
  "polling",
- "rustix",
+ "rustix 0.38.44",
  "slab",
  "thiserror 1.0.69",
 ]
@@ -780,7 +1069,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95a66a987056935f7efce4ab5668920b5d0dac4a7c99991a67395f13702ddd20"
 dependencies = [
  "calloop",
- "rustix",
+ "rustix 0.38.44",
  "wayland-backend",
  "wayland-client",
 ]
@@ -1867,6 +2156,7 @@ version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "25dd34cec49ab55d85ebf70139cb1ccd29c977ef6b6ba4fe85489d6877ee9ef3"
 dependencies = [
+ "accesskit",
  "ahash",
  "bitflags 2.9.1",
  "emath",
@@ -1895,6 +2185,7 @@ version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7d9dfbb78fe4eb9c3a39ad528b90ee5915c252e77bbab9d4ebc576541ab67e13"
 dependencies = [
+ "accesskit_winit",
  "ahash",
  "arboard",
  "bytemuck",
@@ -1996,6 +2287,33 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "endi"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3d8a32ae18130a3c84dd492d4215c3d913c3b07c6b63c2eb3eb7ff1101ab7bf"
+
+[[package]]
+name = "enumflags2"
+version = "0.7.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1027f7680c853e056ebcec683615fb6fbbc07dbaa13b4d5d9442b146ded4ecef"
+dependencies = [
+ "enumflags2_derive",
+ "serde",
+]
+
+[[package]]
+name = "enumflags2_derive"
+version = "0.7.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67c78a4d8fdf9953a5c9d458f9efe940fd97a0cab0941c075a813ac594733827"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "env_filter"
 version = "0.1.3"
@@ -2096,6 +2414,27 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "event-listener"
+version = "5.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3492acde4c3fc54c845eaab3eed8bd00c7a7d881f78bfc801e43a93dec1331ae"
+dependencies = [
+ "concurrent-queue",
+ "parking",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "event-listener-strategy"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8be9f3dfaaffdae2972880079a491a1a8bb7cbed0b8dd7a347f668b4150a3b93"
+dependencies = [
+ "event-listener",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "exr"
 version = "1.73.0"
@@ -2468,6 +2807,19 @@ version = "0.3.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9e5c1b78ca4aae1ac06c48a526a655760685149f0d465d21f37abfe57ce075c6"
 
+[[package]]
+name = "futures-lite"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f5edaec856126859abb19ed65f39e90fea3a9574b9707f13539acf4abf7eb532"
+dependencies = [
+ "fastrand",
+ "futures-core",
+ "futures-io",
+ "parking",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "futures-macro"
 version = "0.3.31"
@@ -3315,6 +3667,12 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "805026a5d0141ffc30abb3be3173848ad46a1b1664fe632428479619a3644d77"
 
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
 [[package]]
 name = "hexf-parse"
 version = "0.2.1"
@@ -4046,6 +4404,15 @@ version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "edcd27d72f2f071c64249075f42e205ff93c9a4c5f6c6da53e79ed9f9832c285"
 
+[[package]]
+name = "immutable-chunkmap"
+version = "2.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12f97096f508d54f8f8ab8957862eee2ccd628847b6217af1a335e1c44dee578"
+dependencies = [
+ "arrayvec",
+]
+
 [[package]]
 name = "imsz"
 version = "0.2.2"
@@ -4554,6 +4921,12 @@ version = "0.4.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d26c52dbd32dccf2d10cac7725f8eae5296885fb5703b261f7d0a0739ec807ab"
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd945864f07fe9f5371a27ad7b52a172b4b499999f1d97574c9fa68373937e12"
+
 [[package]]
 name = "litemap"
 version = "0.7.5"
@@ -5087,6 +5460,7 @@ dependencies = [
  "cfg-if",
  "cfg_aliases",
  "libc",
+ "memoffset",
 ]
 
 [[package]]
@@ -5673,6 +6047,16 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "ordered-stream"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9aa2b01e1d916879f73a53d01d1d6cee68adbb31d6d9177a8cfce093cced1d50"
+dependencies = [
+ "futures-core",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "ordermap"
 version = "0.3.5"
@@ -5704,6 +6088,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "parking"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f38d5652c16fde515bb1ecef450ab0f6a219d619a7274976324d5e377f7dceba"
+
 [[package]]
 name = "parking_lot"
 version = "0.12.4"
@@ -5878,6 +6268,17 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
+[[package]]
+name = "piper"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96c8c490f422ef9a4efd2cb5b42b76c8613d7e7dfc1caf667b8a3350a5acc066"
+dependencies = [
+ "atomic-waker",
+ "fastrand",
+ "futures-io",
+]
+
 [[package]]
 name = "pixels"
 version = "0.0.1"
@@ -5961,7 +6362,7 @@ dependencies = [
  "concurrent-queue",
  "hermit-abi 0.4.0",
  "pin-project-lite",
- "rustix",
+ "rustix 0.38.44",
  "tracing",
  "windows-sys 0.59.0",
 ]
@@ -6139,6 +6540,16 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a993555f31e5a609f617c12db6250dedcac1b0a85076912c436e6fc9b2c8e6a3"
 
+[[package]]
+name = "quick-xml"
+version = "0.30.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eff6510e86862b57b210fd8cbe8ed3f0d7d600b9c2863cd4549a2e033c66e956"
+dependencies = [
+ "memchr",
+ "serde",
+]
+
 [[package]]
 name = "quick-xml"
 version = "0.37.5"
@@ -6486,10 +6897,23 @@ dependencies = [
  "bitflags 2.9.1",
  "errno",
  "libc",
- "linux-raw-sys",
+ "linux-raw-sys 0.4.15",
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "rustix"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c71e83d6afe7ff64890ec6b71d6a69bb8a610ab78ce364b3352876bb4c801266"
+dependencies = [
+ "bitflags 2.9.1",
+ "errno",
+ "libc",
+ "linux-raw-sys 0.9.4",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "rustls"
 version = "0.23.28"
@@ -6862,6 +7286,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_repr"
+version = "0.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "175ee3e80ae9982737ca543e96133087cbd9a485eecc3bc4de9c1a37b47ea59c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "0.6.9"
@@ -7198,6 +7633,7 @@ dependencies = [
 name = "servoshell"
 version = "0.0.1"
 dependencies = [
+ "accesskit_winit",
  "android_logger",
  "backtrace",
  "cc",
@@ -7303,6 +7739,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9203b8055f63a2a00e2f593bb0510367fe707d7ff1e5c872de2f537b339e5410"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "signpost"
 version = "0.1.0"
@@ -7384,7 +7829,7 @@ dependencies = [
  "libc",
  "log",
  "memmap2",
- "rustix",
+ "rustix 0.38.44",
  "thiserror 1.0.69",
  "wayland-backend",
  "wayland-client",
@@ -7842,7 +8287,7 @@ dependencies = [
  "fastrand",
  "getrandom 0.2.16",
  "once_cell",
- "rustix",
+ "rustix 0.38.44",
  "windows-sys 0.52.0",
 ]
 
@@ -8360,6 +8805,17 @@ version = "1.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1dccffe3ce07af9386bfd29e80c0ab1a8205a2fc34e4bcd40364df902cfa8f3f"
 
+[[package]]
+name = "uds_windows"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89daebc3e6fd160ac4aa9fc8b3bf71e1f74fbf92367ae71fb83a037e8bf164b9"
+dependencies = [
+ "memoffset",
+ "tempfile",
+ "winapi",
+]
+
 [[package]]
 name = "uluru"
 version = "3.1.0"
@@ -8754,7 +9210,7 @@ checksum = "fe770181423e5fc79d3e2a7f4410b7799d5aab1de4372853de3c6aa13ca24121"
 dependencies = [
  "cc",
  "downcast-rs",
- "rustix",
+ "rustix 0.38.44",
  "scoped-tls",
  "smallvec",
  "wayland-sys 0.31.6",
@@ -8767,7 +9223,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "978fa7c67b0847dbd6a9f350ca2569174974cd4082737054dbb7fbb79d7d9a61"
 dependencies = [
  "bitflags 2.9.1",
- "rustix",
+ "rustix 0.38.44",
  "wayland-backend",
  "wayland-scanner",
 ]
@@ -8789,7 +9245,7 @@ version = "0.31.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a65317158dec28d00416cb16705934070aef4f8393353d41126c54264ae0f182"
 dependencies = [
- "rustix",
+ "rustix 0.38.44",
  "wayland-client",
  "xcursor",
 ]
@@ -8839,7 +9295,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "896fdafd5d28145fce7958917d69f2fd44469b1d4e861cb5961bcbeebc6d1484"
 dependencies = [
  "proc-macro2",
- "quick-xml",
+ "quick-xml 0.37.5",
  "quote",
 ]
 
@@ -9250,7 +9706,7 @@ dependencies = [
  "either",
  "home",
  "once_cell",
- "rustix",
+ "rustix 0.38.44",
 ]
 
 [[package]]
@@ -9653,7 +10109,7 @@ dependencies = [
  "pin-project",
  "raw-window-handle",
  "redox_syscall 0.4.1",
- "rustix",
+ "rustix 0.38.44",
  "sctk-adwaita",
  "smithay-client-toolkit",
  "smol_str",
@@ -9790,7 +10246,7 @@ dependencies = [
  "libc",
  "libloading",
  "once_cell",
- "rustix",
+ "rustix 0.38.44",
  "x11rb-protocol",
 ]
 
@@ -9807,8 +10263,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e105d177a3871454f754b33bb0ee637ecaaac997446375fd3e5d43a2ed00c909"
 dependencies = [
  "libc",
- "linux-raw-sys",
+ "linux-raw-sys 0.4.15",
- "rustix",
+ "rustix 0.38.44",
 ]
 
 [[package]]
@@ -9828,6 +10284,16 @@ version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "635887f4315a33cb714eb059bdbd7c1c92bfa71bc5b9d5115460502f788c2ab5"
 
+[[package]]
+name = "xdg-home"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec1cdab258fb55c0da61328dc52c8764709b249011b2cad0454c72f0bf10a1f6"
+dependencies = [
+ "libc",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "xi-unicode"
 version = "0.3.0"
@@ -9911,6 +10377,105 @@ dependencies = [
  "synstructure",
 ]
 
+[[package]]
+name = "zbus"
+version = "4.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb97012beadd29e654708a0fdb4c84bc046f537aecfde2c3ee0a9e4b4d48c725"
+dependencies = [
+ "async-broadcast",
+ "async-executor",
+ "async-fs",
+ "async-io",
+ "async-lock",
+ "async-process",
+ "async-recursion",
+ "async-task",
+ "async-trait",
+ "blocking",
+ "enumflags2",
+ "event-listener",
+ "futures-core",
+ "futures-sink",
+ "futures-util",
+ "hex 0.4.3",
+ "nix",
+ "ordered-stream",
+ "rand 0.8.5",
+ "serde",
+ "serde_repr",
+ "sha1",
+ "static_assertions",
+ "tracing",
+ "uds_windows",
+ "windows-sys 0.52.0",
+ "xdg-home",
+ "zbus_macros",
+ "zbus_names",
+ "zvariant",
+]
+
+[[package]]
+name = "zbus-lockstep"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ca2c5dceb099bddaade154055c926bb8ae507a18756ba1d8963fd7b51d8ed1d"
+dependencies = [
+ "zbus_xml",
+ "zvariant",
+]
+
+[[package]]
+name = "zbus-lockstep-macros"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "709ab20fc57cb22af85be7b360239563209258430bccf38d8b979c5a2ae3ecce"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "zbus-lockstep",
+ "zbus_xml",
+ "zvariant",
+]
+
+[[package]]
+name = "zbus_macros"
+version = "4.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "267db9407081e90bbfa46d841d3cbc60f59c0351838c4bc65199ecd79ab1983e"
+dependencies = [
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "zvariant_utils",
+]
+
+[[package]]
+name = "zbus_names"
+version = "3.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b9b1fef7d021261cc16cba64c351d291b715febe0fa10dc3a443ac5a5022e6c"
+dependencies = [
+ "serde",
+ "static_assertions",
+ "zvariant",
+]
+
+[[package]]
+name = "zbus_xml"
+version = "4.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab3f374552b954f6abb4bd6ce979e6c9b38fb9d0cd7cc68a7d796e70c9f3a233"
+dependencies = [
+ "quick-xml 0.30.0",
+ "serde",
+ "static_assertions",
+ "zbus_names",
+ "zvariant",
+]
+
 [[package]]
 name = "zerocopy"
 version = "0.7.35"
@@ -10015,3 +10580,40 @@ checksum = "7384255a918371b5af158218d131530f694de9ad3815ebdd0453a940485cb0fa"
 dependencies = [
  "zune-core",
 ]
+
+[[package]]
+name = "zvariant"
+version = "4.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2084290ab9a1c471c38fc524945837734fbf124487e105daec2bb57fd48c81fe"
+dependencies = [
+ "endi",
+ "enumflags2",
+ "serde",
+ "static_assertions",
+ "zvariant_derive",
+]
+
+[[package]]
+name = "zvariant_derive"
+version = "4.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73e2ba546bda683a90652bac4a279bc146adad1386f25379cf73200d2002c449"
+dependencies = [
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "zvariant_utils",
+]
+
+[[package]]
+name = "zvariant_utils"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c51bcff7cc3dbb5055396bcf774748c3dab426b4b8659046963523cee4808340"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]

deny.toml

@@ -174,6 +174,18 @@ skip = [
 
     # Stylo uses 2.0, WebRender uses 0.99
     "derive_more",
+
+    # duplicated by blurz/blurmock
+    "hex",
+
+    # duplciated by rustix
+    "linux-raw-sys",
+
+    # duplicated by async-io
+    "rustix",
+
+    # duplicated by zbus-xml
+    "quick-xml",
 ]
 
 # github.com organizations to allow git sources for

ports/servoshell/Cargo.toml

@@ -106,10 +106,11 @@ serde_json = { workspace = true }
 surfman = { workspace = true, features = ["sm-angle-default"] }
 
 [target.'cfg(not(any(target_os = "android", target_env = "ohos")))'.dependencies]
+accesskit_winit = "0.23"
 dirs = "6.0"
-egui = "0.31.1"
+egui = { version = "0.31.1", features = ["accesskit"] }
 egui-file-dialog = "0.9.0"
-egui-winit = { version = "0.31.1", default-features = false, features = ["clipboard", "wayland"] }
+egui-winit = { version = "0.31.1", default-features = false, features = ["accesskit", "clipboard", "wayland"] }
 egui_glow = { version = "0.31.1", features = ["winit"] }
 gilrs = "0.11.0"
 glow = "0.16.0"

ports/servoshell/desktop/app.rs

@@ -27,7 +27,7 @@ use winit::event_loop::{ActiveEventLoop, ControlFlow};
 use winit::window::WindowId;
 
 use super::app_state::AppState;
-use super::events_loop::{EventsLoop, WakerEvent};
+use super::events_loop::{AppEvent, EventLoopProxy, EventsLoop};
 use super::minibrowser::{Minibrowser, MinibrowserEvent};
 use super::{headed_window, headless_window};
 use crate::desktop::app_state::RunningAppState;
@@ -45,6 +45,7 @@ pub struct App {
     suspended: Cell<bool>,
     minibrowser: Option<Minibrowser>,
     waker: Box<dyn EventLoopWaker>,
+    proxy: Option<EventLoopProxy>,
     initial_url: ServoUrl,
     t_start: Instant,
     t: Instant,
@@ -89,6 +90,7 @@ impl App {
             windows: HashMap::new(),
             minibrowser: None,
             waker: events_loop.create_event_loop_waker(),
+            proxy: events_loop.event_loop_proxy(),
             initial_url: initial_url.clone(),
             t_start: t,
             t,
@@ -103,10 +105,12 @@ impl App {
         assert_eq!(headless, event_loop.is_none());
         let window = match event_loop {
             Some(event_loop) => {
+                let proxy = self.proxy.take().expect("Must have a proxy available");
                 let window = headed_window::Window::new(&self.servoshell_preferences, event_loop);
                 self.minibrowser = Some(Minibrowser::new(
-                    window.offscreen_rendering_context(),
+                    &window,
                     event_loop,
+                    proxy,
                     self.initial_url.clone(),
                 ));
                 Rc::new(window)
@@ -238,7 +242,7 @@ impl App {
     /// continue.
     pub fn handle_events_with_headless(&mut self) -> bool {
         let now = Instant::now();
-        let event = winit::event::Event::UserEvent(WakerEvent);
+        let event = winit::event::Event::UserEvent(AppEvent::Waker);
         trace_winit_event!(
             event,
             "@{:?} (+{:?}) {event:?}",
@@ -360,7 +364,7 @@ impl App {
     }
 }
 
-impl ApplicationHandler<WakerEvent> for App {
+impl ApplicationHandler<AppEvent> for App {
     fn resumed(&mut self, event_loop: &ActiveEventLoop) {
         self.init(Some(event_loop));
     }
@@ -468,7 +472,20 @@ impl ApplicationHandler<WakerEvent> for App {
         self.handle_events_with_winit(event_loop, window);
     }
 
-    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: WakerEvent) {
+    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: AppEvent) {
+        if let AppEvent::Accessibility(ref event) = event {
+            let Some(ref mut minibrowser) = self.minibrowser else {
+                return;
+            };
+            if !minibrowser.handle_accesskit_event(&event.window_event) {
+                return;
+            }
+            if let Some(window) = self.windows.get(&event.window_id) {
+                window.winit_window().unwrap().request_redraw();
+            }
+            return;
+        }
+
         let now = Instant::now();
         let event = winit::event::Event::UserEvent(event);
         trace_winit_event!(

ports/servoshell/desktop/egui_glue.rs

@@ -41,6 +41,10 @@ use egui_winit::winit;
 use winit::event_loop::ActiveEventLoop;
 use winit::window::Theme;
 
+use super::events_loop::EventLoopProxy;
+use super::headed_window::Window;
+use super::window_trait::WindowPortsMethods;
+
 /// Use [`egui`] from a [`glow`] app based on [`winit`].
 pub struct EguiGlow {
     pub egui_ctx: egui::Context,
@@ -54,7 +58,9 @@ pub struct EguiGlow {
 impl EguiGlow {
     /// For automatic shader version detection set `shader_version` to `None`.
     pub fn new(
+        window: &Window,
         event_loop: &ActiveEventLoop,
+        event_loop_proxy: EventLoopProxy,
         gl: std::sync::Arc<glow::Context>,
         shader_version: Option<ShaderVersion>,
     ) -> Self {
@@ -66,15 +72,19 @@ impl EguiGlow {
 
         let theme = event_loop.system_theme().unwrap_or(Theme::Light);
         let egui_ctx = egui::Context::default();
+        let mut egui_winit = egui_winit::State::new(
+            egui_ctx.clone(),
+            ViewportId::ROOT,
+            event_loop,
+            None,
+            Some(theme),
+            None,
+        );
+        let window = window.winit_window().unwrap();
+        egui_winit.init_accesskit(window, event_loop_proxy);
+        window.set_visible(true);
         Self {
-            egui_winit: egui_winit::State::new(
+            egui_winit,
-                egui_ctx.clone(),
-                ViewportId::ROOT,
-                event_loop,
-                None,
-                Some(theme),
-                None,
-            ),
             egui_ctx,
             painter,
             shapes: Default::default(),

ports/servoshell/desktop/events_loop.rs

@@ -16,15 +16,26 @@ use winit::platform::macos::{ActivationPolicy, EventLoopBuilderExtMacOS};
 
 use super::app::App;
 
-/// Another process or thread has kicked the OS event loop with EventLoopWaker.
+pub type EventLoopProxy = winit::event_loop::EventLoopProxy<AppEvent>;
+
 #[derive(Debug)]
-pub struct WakerEvent;
+pub enum AppEvent {
+    /// Another process or thread has kicked the OS event loop with EventLoopWaker.
+    Waker,
+    Accessibility(accesskit_winit::Event),
+}
+
+impl From<accesskit_winit::Event> for AppEvent {
+    fn from(event: accesskit_winit::Event) -> AppEvent {
+        AppEvent::Accessibility(event)
+    }
+}
 
 /// The real or fake OS event loop.
 #[allow(dead_code)]
 enum EventLoop {
     /// A real Winit windowing event loop.
-    Winit(Option<winit::event_loop::EventLoop<WakerEvent>>),
+    Winit(winit::event_loop::EventLoop<AppEvent>),
     /// A fake event loop which contains a signalling flag used to ensure
     /// that pending events get processed in a timely fashion, and a condition
     /// variable to allow waiting on that flag changing state.
@@ -38,16 +49,16 @@ impl EventsLoop {
     // but on Linux, the event loop requires a X11 server.
     #[cfg(not(any(target_os = "linux", target_os = "macos")))]
     pub fn new(_headless: bool, _has_output_file: bool) -> Result<EventsLoop, EventLoopError> {
-        Ok(EventsLoop(EventLoop::Winit(Some(
+        Ok(EventsLoop(EventLoop::Winit(
             WinitEventLoop::with_user_event().build()?,
-        ))))
+        )))
     }
     #[cfg(target_os = "linux")]
     pub fn new(headless: bool, _has_output_file: bool) -> Result<EventsLoop, EventLoopError> {
         Ok(EventsLoop(if headless {
             EventLoop::Headless(Arc::new((Mutex::new(false), Condvar::new())))
         } else {
-            EventLoop::Winit(Some(WinitEventLoop::with_user_event().build()?))
+            EventLoop::Winit(WinitEventLoop::with_user_event().build()?)
         }))
     }
     #[cfg(target_os = "macos")]
@@ -61,20 +72,22 @@ impl EventsLoop {
                 // when generating an output file.
                 event_loop_builder.with_activation_policy(ActivationPolicy::Prohibited);
             }
-            EventLoop::Winit(Some(event_loop_builder.build()?))
+            EventLoop::Winit(event_loop_builder.build()?)
         }))
     }
 }
 
 impl EventsLoop {
+    pub(crate) fn event_loop_proxy(&self) -> Option<EventLoopProxy> {
+        match self.0 {
+            EventLoop::Winit(ref events_loop) => Some(events_loop.create_proxy()),
+            EventLoop::Headless(..) => None,
+        }
+    }
+
     pub fn create_event_loop_waker(&self) -> Box<dyn EventLoopWaker> {
         match self.0 {
-            EventLoop::Winit(ref events_loop) => {
+            EventLoop::Winit(ref events_loop) => Box::new(HeadedEventLoopWaker::new(events_loop)),
-                let events_loop = events_loop
-                    .as_ref()
-                    .expect("Can't create waker for unavailable event loop.");
-                Box::new(HeadedEventLoopWaker::new(events_loop))
-            },
             EventLoop::Headless(ref data) => Box::new(HeadlessEventLoopWaker(data.clone())),
         }
     }
@@ -82,7 +95,6 @@ impl EventsLoop {
     pub fn run_app(self, app: &mut App) {
         match self.0 {
             EventLoop::Winit(events_loop) => {
-                let events_loop = events_loop.expect("Can't run an unavailable event loop.");
                 events_loop
                     .run_app(app)
                     .expect("Failed while running events loop");
@@ -121,10 +133,10 @@ impl EventsLoop {
 }
 
 struct HeadedEventLoopWaker {
-    proxy: Arc<Mutex<winit::event_loop::EventLoopProxy<WakerEvent>>>,
+    proxy: Arc<Mutex<winit::event_loop::EventLoopProxy<AppEvent>>>,
 }
 impl HeadedEventLoopWaker {
-    fn new(events_loop: &winit::event_loop::EventLoop<WakerEvent>) -> HeadedEventLoopWaker {
+    fn new(events_loop: &winit::event_loop::EventLoop<AppEvent>) -> HeadedEventLoopWaker {
         let proxy = Arc::new(Mutex::new(events_loop.create_proxy()));
         HeadedEventLoopWaker { proxy }
     }
@@ -132,7 +144,7 @@ impl HeadedEventLoopWaker {
 impl EventLoopWaker for HeadedEventLoopWaker {
     fn wake(&self) {
         // Kick the OS event loop awake.
-        if let Err(err) = self.proxy.lock().unwrap().send_event(WakerEvent) {
+        if let Err(err) = self.proxy.lock().unwrap().send_event(AppEvent::Waker) {
             warn!("Failed to wake up event loop ({}).", err);
         }
     }

ports/servoshell/desktop/headed_window.rs

@@ -92,7 +92,9 @@ impl Window {
             .with_transparent(no_native_titlebar)
             .with_inner_size(LogicalSize::new(window_size.width, window_size.height))
             .with_min_inner_size(LogicalSize::new(1, 1))
-            .with_visible(true);
+            // Must be invisible at startup; accesskit_winit setup needs to
+            // happen before the window is shown for the first time.
+            .with_visible(false);
 
         #[allow(deprecated)]
         let winit_window = event_loop

ports/servoshell/desktop/minibrowser.rs

@@ -29,7 +29,9 @@ use winit::window::Window;
 
 use super::app_state::RunningAppState;
 use super::egui_glue::EguiGlow;
+use super::events_loop::EventLoopProxy;
 use super::geometry::winit_position_to_euclid_point;
+use super::headed_window::Window as ServoWindow;
 
 pub struct Minibrowser {
     rendering_context: Rc<OffscreenRenderingContext>,
@@ -76,13 +78,21 @@ impl Drop for Minibrowser {
 
 impl Minibrowser {
     pub fn new(
-        rendering_context: Rc<OffscreenRenderingContext>,
+        window: &ServoWindow,
         event_loop: &ActiveEventLoop,
+        event_loop_proxy: EventLoopProxy,
         initial_url: ServoUrl,
     ) -> Self {
+        let rendering_context = window.offscreen_rendering_context();
         // Adapted from https://github.com/emilk/egui/blob/9478e50d012c5138551c38cbee16b07bc1fcf283/crates/egui_glow/examples/pure_glow.rs
         #[allow(clippy::arc_with_non_send_sync)]
-        let context = EguiGlow::new(event_loop, rendering_context.glow_gl_api(), None);
+        let context = EguiGlow::new(
+            window,
+            event_loop,
+            event_loop_proxy,
+            rendering_context.glow_gl_api(),
+            None,
+        );
 
         // Disable the builtin egui handlers for the Ctrl+Plus, Ctrl+Minus and Ctrl+0
         // shortcuts as they don't work well with servoshell's `device-pixel-ratio` CLI argument.
@@ -489,4 +499,24 @@ impl Minibrowser {
             self.update_load_status(state) |
             self.update_status_text(state)
     }
+
+    /// Returns true if a redraw is required after handling the provided event.
+    pub(crate) fn handle_accesskit_event(&mut self, event: &accesskit_winit::WindowEvent) -> bool {
+        match event {
+            accesskit_winit::WindowEvent::InitialTreeRequested => {
+                self.context.egui_ctx.enable_accesskit();
+                true
+            },
+            accesskit_winit::WindowEvent::ActionRequested(req) => {
+                self.context
+                    .egui_winit
+                    .on_accesskit_action_request(req.clone());
+                true
+            },
+            accesskit_winit::WindowEvent::AccessibilityDeactivated => {
+                self.context.egui_ctx.disable_accesskit();
+                false
+            },
+        }
+    }
 }

ports/servoshell/desktop/tracing.rs

@@ -11,7 +11,7 @@
 ///   - servoshell<winit@NewEvents(WaitCancelled)=off
 ///   - servoshell<winit@RedrawEventsCleared=off
 ///   - servoshell<winit@RedrawRequested=off
-///   - servoshell<winit@UserEvent(WakerEvent)=off
+///   - servoshell<winit@UserEvent(Waker)=off
 ///   - servoshell<winit@WindowEvent(AxisMotion)=off
 ///   - servoshell<winit@WindowEvent(CursorMoved)=off
 macro_rules! trace_winit_event {
@@ -31,7 +31,7 @@ pub(crate) trait LogTarget {
 
 mod from_winit {
     use super::LogTarget;
-    use crate::desktop::events_loop::WakerEvent;
+    use crate::desktop::events_loop::AppEvent;
 
     macro_rules! target {
         ($($name:literal)+) => {
@@ -39,7 +39,7 @@ mod from_winit {
         };
     }
 
-    impl LogTarget for winit::event::Event<WakerEvent> {
+    impl LogTarget for winit::event::Event<AppEvent> {
         fn log_target(&self) -> &'static str {
             use winit::event::StartCause;
             match self {
@@ -51,7 +51,8 @@ mod from_winit {
                 },
                 Self::WindowEvent { event, .. } => event.log_target(),
                 Self::DeviceEvent { .. } => target!("DeviceEvent"),
-                Self::UserEvent(WakerEvent) => target!("UserEvent(WakerEvent)"),
+                Self::UserEvent(AppEvent::Waker) => target!("UserEvent(Waker)"),
+                Self::UserEvent(AppEvent::Accessibility(..)) => target!("UserEvent(Accessibility)"),
                 Self::Suspended => target!("Suspended"),
                 Self::Resumed => target!("Resumed"),
                 Self::AboutToWait => target!("AboutToWait"),