diff --git a/Cargo.lock b/Cargo.lock
index a586bdf6010..ee28bed693f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -292,7 +292,7 @@ dependencies = [
  "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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -306,7 +306,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -427,8 +427,8 @@ 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 0.25.0 (git+https://github.com/servo/webrender)",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -461,7 +461,7 @@ dependencies = [
  "servo_remutex 0.0.1",
  "servo_url 0.0.1",
  "style_traits 0.0.1",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
  "webvr_traits 0.0.1",
 ]
 
@@ -706,7 +706,7 @@ dependencies = [
  "servo_geometry 0.0.1",
  "servo_url 0.0.1",
  "style_traits 0.0.1",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
  "x11 2.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -988,7 +988,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
  "xi-unicode 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1067,7 +1067,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (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)",
 ]
@@ -1378,7 +1378,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1418,7 +1418,7 @@ dependencies = [
  "servo_geometry 0.0.1",
  "servo_url 0.0.1",
  "style 0.0.1",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1432,7 +1432,7 @@ dependencies = [
  "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "servo_url 0.0.1",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1517,8 +1517,8 @@ dependencies = [
  "style 0.0.1",
  "style_traits 0.0.1",
  "webdriver_server 0.0.1",
- "webrender 0.25.0 (git+https://github.com/servo/webrender)",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
  "webvr 0.0.1",
  "webvr_traits 0.0.1",
 ]
@@ -1667,7 +1667,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1709,7 +1709,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -1767,7 +1767,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
@@ -2312,7 +2312,7 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
  "webvr 0.0.1",
  "webvr_traits 0.0.1",
  "xml5ever 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3186,8 +3186,8 @@ dependencies = [
 
 [[package]]
 name = "webrender"
-version = "0.25.0"
-source = "git+https://github.com/servo/webrender#0794911f97cae92496fca992d7430da696fa24eb"
+version = "0.26.0"
+source = "git+https://github.com/servo/webrender#b2dd9f792d0cb3dfc591567c105755f56f35956d"
 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)",
@@ -3209,13 +3209,13 @@ 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 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
 ]
 
 [[package]]
 name = "webrender_traits"
-version = "0.26.0"
-source = "git+https://github.com/servo/webrender#0794911f97cae92496fca992d7430da696fa24eb"
+version = "0.27.0"
+source = "git+https://github.com/servo/webrender#b2dd9f792d0cb3dfc591567c105755f56f35956d"
 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)",
@@ -3239,7 +3239,7 @@ dependencies = [
  "msg 0.0.1",
  "script_traits 0.0.1",
  "servo_config 0.0.1",
- "webrender_traits 0.26.0 (git+https://github.com/servo/webrender)",
+ "webrender_traits 0.27.0 (git+https://github.com/servo/webrender)",
  "webvr_traits 0.0.1",
 ]
 
@@ -3582,8 +3582,8 @@ 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 0.20.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cdc28802daddee94267a657ffeac2593a33881fb7a3a44fedd320b1319efcaf6"
-"checksum webrender 0.25.0 (git+https://github.com/servo/webrender)" = "<none>"
-"checksum webrender_traits 0.26.0 (git+https://github.com/servo/webrender)" = "<none>"
+"checksum webrender 0.26.0 (git+https://github.com/servo/webrender)" = "<none>"
+"checksum webrender_traits 0.27.0 (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"
diff --git a/components/canvas/canvas_paint_thread.rs b/components/canvas/canvas_paint_thread.rs
index 8aca22bdbfb..7f09603d322 100644
--- a/components/canvas/canvas_paint_thread.rs
+++ b/components/canvas/canvas_paint_thread.rs
@@ -567,7 +567,8 @@ impl<'a> CanvasPaintThread<'a> {
                                                 offset: 0,
                                                 is_opaque: false,
                                             },
-                                            element.into());
+                                            element.into(),
+                                            None);
 
             let data = CanvasImageData {
                 image_key: self.webrender_image_key,
diff --git a/components/canvas/webgl_paint_thread.rs b/components/canvas/webgl_paint_thread.rs
index 2894df71a06..b5893c15058 100644
--- a/components/canvas/webgl_paint_thread.rs
+++ b/components/canvas/webgl_paint_thread.rs
@@ -261,7 +261,8 @@ impl WebGLPaintThread {
                                                offset: 0,
                                                is_opaque: false,
                                            },
-                                           pixels.clone());
+                                           pixels.clone(),
+                                           None);
 
                 let image_data = CanvasImageData {
                     image_key: image_key,
diff --git a/components/layout/webrender_helpers.rs b/components/layout/webrender_helpers.rs
index 3d2f434053d..8c8427522ef 100644
--- a/components/layout/webrender_helpers.rs
+++ b/components/layout/webrender_helpers.rs
@@ -404,10 +404,6 @@ impl WebRenderDisplayItemConverter for DisplayItem {
                 let stacking_context = &item.stacking_context;
                 debug_assert!(stacking_context.context_type == StackingContextType::Real);
 
-                let clip = builder.new_clip_region(&stacking_context.overflow.to_rectf(),
-                                                   vec![],
-                                                   None);
-
                 let transform = stacking_context.transform.map(|transform| {
                     LayoutTransform::from_untyped(&transform).into()
                 });
@@ -417,7 +413,6 @@ impl WebRenderDisplayItemConverter for DisplayItem {
 
                 builder.push_stacking_context(stacking_context.scroll_policy,
                                               stacking_context.bounds.to_rectf(),
-                                              clip,
                                               stacking_context.z_index,
                                               transform,
                                               perspective,
diff --git a/tests/wpt/metadata-css/css-values-3_dev/html/calc-border-radius-1.htm.ini b/tests/wpt/metadata-css/css-values-3_dev/html/calc-border-radius-1.htm.ini
deleted file mode 100644
index e4eef061c0c..00000000000
--- a/tests/wpt/metadata-css/css-values-3_dev/html/calc-border-radius-1.htm.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[calc-border-radius-1.htm]
-  type: reftest
-  expected: FAIL
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index b891057aa26..20fa194cd84 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -24037,7 +24037,7 @@
    "reftest"
   ],
   "css/viewport_rule_ref.html": [
-   "00bb1ce6ccffc6b6bb0db1565985171ff49f1362",
+   "aa1693b5917599430c3520cc7aebdd275d4c6f19",
    "support"
   ],
   "css/visibility_hidden.html": [
diff --git a/tests/wpt/metadata-css/css-transforms-1_dev/html/transform-abspos-006.htm.ini b/tests/wpt/mozilla/meta/css/border_black_ridge_b.html.ini
similarity index 54%
rename from tests/wpt/metadata-css/css-transforms-1_dev/html/transform-abspos-006.htm.ini
rename to tests/wpt/mozilla/meta/css/border_black_ridge_b.html.ini
index dd344308dfd..77a903e94d5 100644
--- a/tests/wpt/metadata-css/css-transforms-1_dev/html/transform-abspos-006.htm.ini
+++ b/tests/wpt/mozilla/meta/css/border_black_ridge_b.html.ini
@@ -1,3 +1,3 @@
-[transform-abspos-006.htm]
+[border_black_ridge_b.html]
   type: reftest
   expected: FAIL
diff --git a/tests/wpt/mozilla/tests/css/viewport_rule_ref.html b/tests/wpt/mozilla/tests/css/viewport_rule_ref.html
index 2cd2b347d3f..4c7be62919a 100644
--- a/tests/wpt/mozilla/tests/css/viewport_rule_ref.html
+++ b/tests/wpt/mozilla/tests/css/viewport_rule_ref.html
@@ -5,7 +5,7 @@
       #container {
         background: blue;
         height: 180px;
-        width: 232px;
+        width: 240px;
       }
 
       #box {