Update WR (various optimizations, gradient improvements).

Cargo.lock

@@ -291,13 +291,13 @@ dependencies = [
  "canvas_traits 0.0.1",
  "cssparser 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_config 0.0.1",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -311,7 +311,7 @@ dependencies = [
  "ipc-channel 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.9.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 0.9.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -341,7 +341,7 @@ name = "cgl"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -419,7 +419,7 @@ version = "0.0.1"
 dependencies = [
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gfx_traits 0.0.1",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -432,8 +432,8 @@ dependencies = [
  "servo_url 0.0.1",
  "style_traits 0.0.1",
  "time 0.1.36 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender 0.27.0 (git+https://github.com/servo/webrender)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -467,7 +467,7 @@ dependencies = [
  "servo_remutex 0.0.1",
  "servo_url 0.0.1",
  "style_traits 0.0.1",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "webvr_traits 0.0.1",
 ]
 
@@ -696,7 +696,7 @@ dependencies = [
  "compositing 0.0.1",
  "devtools 0.0.1",
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "glutin_app 0.0.1",
  "libc 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "libservo 0.0.1",
@@ -709,7 +709,7 @@ dependencies = [
  "servo_geometry 0.0.1",
  "servo_url 0.0.1",
  "style_traits 0.0.1",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "x11 2.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -996,7 +996,7 @@ dependencies = [
  "time 0.1.36 (registry+https://github.com/rust-lang/crates.io-index)",
  "truetype 0.26.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-script 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "xi-unicode 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1041,7 +1041,7 @@ dependencies = [
 
 [[package]]
 name = "gleam"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gl_generator 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1061,7 +1061,7 @@ dependencies = [
  "compositing 0.0.1",
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gdi32-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
@@ -1075,7 +1075,7 @@ dependencies = [
  "servo_url 0.0.1",
  "style_traits 0.0.1",
  "user32-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "x11 2.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1261,7 +1261,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cgl 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "leaky-cow 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1385,7 +1385,7 @@ dependencies = [
  "style_traits 0.0.1",
  "unicode-bidi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-script 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1425,7 +1425,7 @@ dependencies = [
  "servo_geometry 0.0.1",
  "servo_url 0.0.1",
  "style 0.0.1",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1439,7 +1439,7 @@ dependencies = [
  "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "servo_url 0.0.1",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1498,7 +1498,7 @@ dependencies = [
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gaol 0.0.1 (git+https://github.com/servo/gaol)",
  "gfx 0.0.1",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "layout_thread 0.0.1",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1516,8 +1516,8 @@ dependencies = [
  "style 0.0.1",
  "style_traits 0.0.1",
  "webdriver_server 0.0.1",
- "webrender 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender 0.27.0 (git+https://github.com/servo/webrender)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "webvr 0.0.1",
  "webvr_traits 0.0.1",
 ]
@@ -1666,7 +1666,7 @@ dependencies = [
  "heapsize_derive 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.9.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 0.9.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1708,7 +1708,7 @@ dependencies = [
  "unicase 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1768,7 +1768,7 @@ dependencies = [
  "servo_url 0.0.1",
  "url 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1857,7 +1857,7 @@ dependencies = [
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gdi32-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gl_generator 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2286,7 +2286,7 @@ dependencies = [
  "tinyfiledialogs 2.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "webvr 0.0.1",
  "webvr_traits 0.0.1",
  "xml5ever 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2507,7 +2507,7 @@ dependencies = [
  "cmake 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "expat-sys 2.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "glx 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "io-surface 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3144,8 +3144,8 @@ dependencies = [
 
 [[package]]
 name = "webrender"
-version = "0.26.0"
+version = "0.27.0"
-source = "git+https://github.com/servo/webrender#b2dd9f792d0cb3dfc591567c105755f56f35956d"
+source = "git+https://github.com/servo/webrender#4b72bb1921628d01b08ab356c0f2365a927b711e"
 dependencies = [
  "app_units 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0-alpha2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3159,7 +3159,7 @@ dependencies = [
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "freetype 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gamma-lut 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3167,20 +3167,20 @@ dependencies = [
  "thread_profiler 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "threadpool 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.36 (registry+https://github.com/rust-lang/crates.io-index)",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
 name = "webrender_traits"
-version = "0.27.0"
+version = "0.28.0"
-source = "git+https://github.com/servo/webrender#b2dd9f792d0cb3dfc591567c105755f56f35956d"
+source = "git+https://github.com/servo/webrender#4b72bb1921628d01b08ab356c0f2365a927b711e"
 dependencies = [
  "app_units 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "dwrote 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3197,7 +3197,7 @@ dependencies = [
  "msg 0.0.1",
  "script_traits 0.0.1",
  "servo_config 0.0.1",
- "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.28.0 (git+https://github.com/servo/webrender)",
  "webvr_traits 0.0.1",
 ]
 
@@ -3375,7 +3375,7 @@ dependencies = [
 "checksum getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9047cfbd08a437050b363d35ef160452c5fe8ea5187ae0a624708c91581d685"
 "checksum gif 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8a80d6fe9e52f637df9afd4779449a7be17c39cc9c35b01589bb833f956ba596"
 "checksum gl_generator 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f1d8edc81c5ae84605a62f5dac661a2313003b26d59839f81d47d46cf0f16a55"
-"checksum gleam 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2958396a0a358d2de747b31329f5ae2229070602b0f51edd5d682f92c307c332"
+"checksum gleam 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3232655dbe4fc5ab688c05024f2c816b5d20c19ad8216d5c7d85cf915b24e005"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
 "checksum glx 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b280007fa9c7442cfd1e0b1addb8d1a59240267110e8705f8f7e2c7bfb7e2f72"
 "checksum harfbuzz-sys 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "6b76113246f5c089dcf272cf89c3f61168a4d77b50ec5b2c1fab8c628c9ea762"
@@ -3536,8 +3536,8 @@ dependencies = [
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum walkdir 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "bb08f9e670fab86099470b97cd2b252d6527f0b3cc1401acdb595ffc9dd288ff"
 "checksum webdriver 0.22.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d548aabf87411b1b4ba91fd07eacd8b238135c7131a452b8a9f6386209167e18"
-"checksum webrender 0.26.0 (git+https://github.com/servo/webrender)" = "<none>"
+"checksum webrender 0.27.0 (git+https://github.com/servo/webrender)" = "<none>"
-"checksum webrender_traits 0.27.0 (git+https://github.com/servo/webrender)" = "<none>"
+"checksum webrender_traits 0.28.0 (git+https://github.com/servo/webrender)" = "<none>"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
 "checksum ws 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "04614a58714f3fd4a8b1da4bcae9f031c532d35988c3d39627619248113f8be8"

components/canvas/canvas_paint_thread.rs

@@ -18,6 +18,7 @@ use ipc_channel::ipc::{self, IpcSender};
 use num_traits::ToPrimitive;
 use std::borrow::ToOwned;
 use std::mem;
+use std::sync::Arc;
 use std::thread;
 use webrender_traits;
 
@@ -60,7 +61,7 @@ pub struct CanvasPaintThread<'a> {
     state: CanvasPaintState<'a>,
     saved_states: Vec<CanvasPaintState<'a>>,
     webrender_api: webrender_traits::RenderApi,
-    webrender_image_key: webrender_traits::ImageKey,
+    image_key: Option<webrender_traits::ImageKey>,
 }
 
 #[derive(Clone)]
@@ -106,14 +107,13 @@ impl<'a> CanvasPaintThread<'a> {
         let draw_target = CanvasPaintThread::create(size);
         let path_builder = draw_target.create_path_builder();
         let webrender_api = webrender_api_sender.create_api();
-        let webrender_image_key = webrender_api.generate_image_key();
         CanvasPaintThread {
             drawtarget: draw_target,
             path_builder: path_builder,
             state: CanvasPaintState::new(antialias),
             saved_states: vec![],
             webrender_api: webrender_api,
-            webrender_image_key: webrender_image_key,
+            image_key: None,
         }
     }
 
@@ -558,20 +558,35 @@ impl<'a> CanvasPaintThread<'a> {
     fn send_data(&mut self, chan: IpcSender<CanvasData>) {
         self.drawtarget.snapshot().get_data_surface().with_data(|element| {
             let size = self.drawtarget.get_size();
-            self.webrender_api.update_image(self.webrender_image_key,
+
-                                            webrender_traits::ImageDescriptor {
+            let descriptor = webrender_traits::ImageDescriptor {
-                                                width: size.width as u32,
+                width: size.width as u32,
-                                                height: size.height as u32,
+                height: size.height as u32,
-                                                stride: None,
+                stride: None,
-                                                format: webrender_traits::ImageFormat::RGBA8,
+                format: webrender_traits::ImageFormat::RGBA8,
-                                                offset: 0,
+                offset: 0,
-                                                is_opaque: false,
+                is_opaque: false,
-                                            },
+            };
-                                            element.into(),
+            let data = webrender_traits::ImageData::Raw(Arc::new(element.into()));
-                                            None);
+
+            match self.image_key {
+                Some(image_key) => {
+                    self.webrender_api.update_image(image_key,
+                                                    descriptor,
+                                                    data,
+                                                    None);
+                }
+                None => {
+                    self.image_key = Some(self.webrender_api.generate_image_key());
+                    self.webrender_api.add_image(self.image_key.unwrap(),
+                                                 descriptor,
+                                                 data,
+                                                 None);
+                }
+            }
 
             let data = CanvasImageData {
-                image_key: self.webrender_image_key,
+                image_key: self.image_key.unwrap(),
             };
             chan.send(CanvasData::Image(data)).unwrap();
         })
@@ -728,7 +743,9 @@ impl<'a> CanvasPaintThread<'a> {
 
 impl<'a> Drop for CanvasPaintThread<'a> {
     fn drop(&mut self) {
-        self.webrender_api.delete_image(self.webrender_image_key);
+        if let Some(image_key) = self.image_key {
+            self.webrender_api.delete_image(image_key);
+        }
     }
 }
 

components/canvas/webgl_paint_thread.rs

@@ -11,6 +11,7 @@ use offscreen_gl_context::{ColorAttachmentType, GLContext, GLLimits};
 use offscreen_gl_context::{GLContextAttributes, NativeGLContext, OSMesaContext};
 use servo_config::opts;
 use std::borrow::ToOwned;
+use std::sync::Arc;
 use std::sync::mpsc::channel;
 use std::thread;
 use webrender_traits;
@@ -101,7 +102,7 @@ impl GLContextWrapper {
 
 enum WebGLPaintTaskData {
     WebRender(webrender_traits::RenderApi, webrender_traits::WebGLContextId),
-    Readback(GLContextWrapper, webrender_traits::RenderApi, webrender_traits::ImageKey),
+    Readback(GLContextWrapper, webrender_traits::RenderApi, Option<webrender_traits::ImageKey>),
 }
 
 pub struct WebGLPaintThread {
@@ -116,10 +117,9 @@ fn create_readback_painter(size: Size2D<i32>,
     -> Result<(WebGLPaintThread, GLLimits), String> {
     let context = try!(GLContextWrapper::new(size, attrs, gl_type));
     let limits = context.get_limits();
-    let image_key = webrender_api.generate_image_key();
     let painter = WebGLPaintThread {
         size: size,
-        data: WebGLPaintTaskData::Readback(context, webrender_api, image_key)
+        data: WebGLPaintTaskData::Readback(context, webrender_api, None)
     };
 
     Ok((painter, limits))
@@ -229,7 +229,7 @@ impl WebGLPaintThread {
 
     fn send_data(&mut self, chan: IpcSender<CanvasData>) {
         match self.data {
-            WebGLPaintTaskData::Readback(ref ctx, ref webrender_api, image_key) => {
+            WebGLPaintTaskData::Readback(ref ctx, ref webrender_api, ref mut image_key) => {
                 let width = self.size.width as usize;
                 let height = self.size.height as usize;
 
@@ -250,22 +250,34 @@ impl WebGLPaintThread {
                 // rgba -> bgra
                 byte_swap(&mut pixels);
 
-                // TODO: This shouldn't be a common path, but try to avoid
+                let descriptor = webrender_traits::ImageDescriptor {
-                // the spurious clone().
+                    width: width as u32,
-                webrender_api.update_image(image_key,
+                    height: height as u32,
-                                           webrender_traits::ImageDescriptor {
+                    stride: None,
-                                               width: width as u32,
+                    format: webrender_traits::ImageFormat::RGBA8,
-                                               height: height as u32,
+                    offset: 0,
-                                               stride: None,
+                    is_opaque: false,
-                                               format: webrender_traits::ImageFormat::RGBA8,
+                };
-                                               offset: 0,
+                let data = webrender_traits::ImageData::Raw(Arc::new(pixels));
-                                               is_opaque: false,
+
-                                           },
+                match *image_key {
-                                           pixels.clone(),
+                    Some(image_key) => {
-                                           None);
+                        webrender_api.update_image(image_key,
+                                                   descriptor,
+                                                   data,
+                                                   None);
+                    }
+                    None => {
+                        *image_key = Some(webrender_api.generate_image_key());
+                        webrender_api.add_image(image_key.unwrap(),
+                                                descriptor,
+                                                data,
+                                                None);
+                    }
+                }
 
                 let image_data = CanvasImageData {
-                    image_key: image_key,
+                    image_key: image_key.unwrap(),
                 };
 
                 chan.send(CanvasData::Image(image_data)).unwrap();
@@ -307,7 +319,9 @@ impl WebGLPaintThread {
 impl Drop for WebGLPaintThread {
     fn drop(&mut self) {
         if let WebGLPaintTaskData::Readback(_, ref mut wr, image_key) = self.data {
-            wr.delete_image(image_key);
+            if let Some(image_key) = image_key {
+                wr.delete_image(image_key);
+            }
         }
     }
 }

components/compositing/compositor.rs

@@ -76,9 +76,12 @@ trait ConvertScrollRootIdFromWebRender {
     fn from_webrender(&self) -> ScrollRootId;
 }
 
-impl ConvertScrollRootIdFromWebRender for usize {
+impl ConvertScrollRootIdFromWebRender for u64 {
     fn from_webrender(&self) -> ScrollRootId {
-        ScrollRootId(*self)
+        // This conversion is lossy on 32 bit platforms,
+        // but we only actually use the bottom 32 bits
+        // on Servo anyway.
+        ScrollRootId(*self as usize)
     }
 }
 
@@ -794,7 +797,7 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                                 pipeline_id: PipelineId,
                                 scroll_root_id: ScrollRootId,
                                 point: Point2D<f32>) {
-        let id = ScrollLayerId::new(scroll_root_id.0, pipeline_id.to_webrender());
+        let id = ScrollLayerId::new(scroll_root_id.0 as u64, pipeline_id.to_webrender());
         self.webrender_api.scroll_layer_with_id(LayoutPoint::from_untyped(&point), id);
     }
 

components/layout/webrender_helpers.rs

@@ -425,7 +425,7 @@ impl WebRenderDisplayItemConverter for DisplayItem {
                                                    vec![],
                                                    None);
 
-                let provided_id = ScrollLayerId::new(item.scroll_root.id.0, builder.pipeline_id);
+                let provided_id = ScrollLayerId::new(item.scroll_root.id.0 as u64, builder.pipeline_id);
                 let id = builder.define_clip(clip,
                                              item.scroll_root.size.to_sizef(),
                                              Some(provided_id));
@@ -444,7 +444,7 @@ impl WebRenderScrollRootIdConverter for ScrollRootId {
         if *self == ScrollRootId::root() {
             ScrollLayerId::root_scroll_layer(pipeline_id)
         } else {
-            ScrollLayerId::new(self.0, pipeline_id)
+            ScrollLayerId::new(self.0 as u64, pipeline_id)
         }
     }
 }