Enable kCompositeCrossOriginIframes by default

This feature is required for isInputPending.

The change to compositing_inputs_updater.cc fixes a bug that snuck in
via this CL while the feature was disabled:

https://chromium-review.googlesource.com/c/chromium/src/+/2283630

The web_test changes are mostly cases where a test has a cross-origin
iframe which was not previously composited, and making the iframe
composited caused anti-aliasing differences. The mhtml/ test changes
are needed because chromium treats the iframes in the encoded-html
test files as cross-origin; to ensure consistent text rendering, this
CL forces everything in both the test files and the ref test
expectations to be composited.

BUG=930987

Change-Id: I8f54eeacd333e46f394c08e9bf8366f0e9e2e57e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2443630
Commit-Queue: Stefan Zager <szager@chromium.org>
Auto-Submit: Stefan Zager <szager@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815300}

third_party/blink/common/features.cc

@@ -465,7 +465,7 @@ const base::Feature kSubresourceRedirect{"SubresourceRedirect",
 
 // When 'enabled', all cross-origin iframes will get a compositing layer.
 const base::Feature kCompositeCrossOriginIframes{
-    "CompositeCrossOriginIframes", base::FEATURE_DISABLED_BY_DEFAULT};
+    "CompositeCrossOriginIframes", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // When enabled, enforces new interoperable semantics for 3D transforms.
 // See crbug.com/1008483.

third_party/blink/renderer/core/paint/compositing/compositing_inputs_updater.cc

@@ -38,6 +38,10 @@ CompositingInputsUpdater::~CompositingInputsUpdater() = default;
 
 bool CompositingInputsUpdater::LayerOrDescendantShouldBeComposited(
     PaintLayer* layer) {
+  if (layer->GetLayoutObject().IsLayoutView() &&
+      layer->GetLayoutObject().AdditionalCompositingReasons()) {
+    return true;
+  }
   PaintLayerCompositor* compositor =
       layer->GetLayoutObject().View()->Compositor();
   return layer->DescendantHasDirectOrScrollingCompositingReason() ||
@@ -199,13 +203,11 @@ void CompositingInputsUpdater::UpdateSelfAndDescendantsRecursively(
   }
   if (!descendant_has_direct_compositing_reason &&
       layer->GetLayoutObject().IsLayoutEmbeddedContent()) {
-    if (LayoutView* root_of_child =
+    if (LayoutView* embedded_layout_view =
             ToLayoutEmbeddedContent(layer->GetLayoutObject())
                 .ChildLayoutView()) {
-      if (CompositingInputsUpdater(root_of_child->Layer(),
-                                   root_of_child->Layer())
-              .LayerOrDescendantShouldBeComposited(root_of_child->Layer()))
-        descendant_has_direct_compositing_reason = true;
+      descendant_has_direct_compositing_reason |=
+          LayerOrDescendantShouldBeComposited(embedded_layout_view->Layer());
     }
   }
   layer->SetDescendantHasDirectOrScrollingCompositingReason(

third_party/blink/renderer/core/scheduler_integration_tests/frame_throttling_test.cc

@@ -6,6 +6,7 @@
 #include "base/test/bind_test_util.h"
 #include "cc/layers/picture_layer.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features.h"
 #include "third_party/blink/public/web/web_frame_content_dumper.h"
 #include "third_party/blink/public/web/web_hit_test_result.h"
 #include "third_party/blink/public/web/web_settings.h"
@@ -980,6 +981,12 @@ TEST_P(FrameThrottlingTest, ThrottledTopLevelEventHandlerIgnored) {
   WebView().GetSettings()->SetJavaScriptEnabled(true);
   EXPECT_EQ(0u, TouchHandlerRegionSize());
 
+  // This test covers the case where a non-composited iframe is throttled. With
+  // this flag enabled, that is impossible, because only cross-origin iframes
+  // can be throttled.
+  if (base::FeatureList::IsEnabled(features::kCompositeCrossOriginIframes))
+    return;
+
   // Create a frame which is throttled and has two different types of
   // top-level touchstart handlers.
   SimRequest main_resource("https://example.com/", "text/html");
@@ -1027,6 +1034,12 @@ TEST_P(FrameThrottlingTest, ThrottledEventHandlerIgnored) {
   WebView().GetSettings()->SetJavaScriptEnabled(true);
   EXPECT_EQ(0u, TouchHandlerRegionSize());
 
+  // This test covers the case where a non-composited iframe is throttled. With
+  // this flag enabled, that is impossible, because only cross-origin iframes
+  // can be throttled.
+  if (base::FeatureList::IsEnabled(features::kCompositeCrossOriginIframes))
+    return;
+
   // Create a frame which is throttled and has a non-top-level touchstart
   // handler.
   SimRequest main_resource("https://example.com/", "text/html");
@@ -1130,8 +1143,12 @@ TEST_P(FrameThrottlingTest, PaintingViaGraphicsLayerIsThrottled) {
   EXPECT_TRUE(frame_element->contentDocument()->View()->CanThrottleRendering());
 
   // If painting of the iframe is throttled, we should only receive drawing
-  // commands for the main frame.
-  auto commands_throttled = Compositor().PaintFrame();
+  // commands for the main frame. We have to explicitly schedule a frame here
+  // because the iframe becoming throttled will affect the painted output;
+  // but it will not by itself schedule an animation frame, because it doesn't
+  // need display.
+  GetDocument().View()->ScheduleAnimation();
+  auto commands_throttled = CompositeFrame();
   EXPECT_EQ(5u, commands_throttled.DrawCount());
   EXPECT_FALSE(Compositor().NeedsBeginFrame());
 }

third_party/blink/web_tests/flag-specific/composite-after-paint/paint/invalidation/compositing/overlap-test-with-filter-expected.txt

@@ -6,6 +6,12 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
+    {
+      "name": "LayoutView #document",
+      "bounds": [300, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFF00"
+    },
     {
       "name": "LayoutNGBlockFlow BODY",
       "bounds": [284, 84],

third_party/blink/web_tests/http/tests/navigation/resources/focus-shifting-frame-with-anchor.html

 <!DOCTYPE html>
+<body style="will-change:transform">
 <a href='#'>anchor</a>
 <a id='dummy' href='dummy'>dummy</a>
 <div style='width:10px;height:2000px;background:white'></div>
@@ -10,3 +11,4 @@ window.onmousedown = function() {
   });
 }
 </script>
+</body>

third_party/blink/web_tests/mhtml/multi_frames_binary-expected.html

@@ -3,11 +3,16 @@
 
 
 <title>A page that contains multiple nested frames</title>
+<script>
+  if (window.internals) {
+    internals.settings.setPreferCompositingToLCDTextEnabled(true);
+  }
+</script>
 </head><body>
 This page contains several frames.<br>
-<iframe src="resources/frame_0.html"></iframe><br>
-<iframe src="resources/frame_1.html"></iframe><br>
+<iframe sandbox src="resources/frame_0.html"></iframe><br>
+<iframe sandbox src="resources/frame_1.html"></iframe><br>
 <iframe src="resources/frame_2.html"></iframe><br>
-And a red square:<br>
-<img src="resources/red_square.png">
+<div style="will-change:transform">And a red square:<br>
+<img src="resources/red_square.png"></div>
 </body></html>

third_party/blink/web_tests/mhtml/multi_frames_contentid-expected.html

@@ -3,11 +3,16 @@
 
 
 <title>A page that contains multiple nested frames</title>
+<script>
+  if (window.internals) {
+    internals.settings.setPreferCompositingToLCDTextEnabled(true);
+  }
+</script>
 </head><body>
 This page contains several frames.<br>
-<iframe src="resources/frame_0.html"></iframe><br>
-<iframe src="resources/frame_1.html"></iframe><br>
+<iframe sandbox src="resources/frame_0.html"></iframe><br>
+<iframe sandbox src="resources/frame_1.html"></iframe><br>
 <iframe src="resources/frame_2.html"></iframe><br>
-And a red square:<br>
-<img src="resources/red_square.png">
+<div style="will-change:transform">And a red square:<br>
+<img src="resources/red_square.png"></div>
 </body></html>

third_party/blink/web_tests/mhtml/multi_frames_contentid.mht

@@ -21,8 +21,8 @@ This page contains several frames.<br>
 <iframe src=3D"cid:frame0@foo.bar"></iframe><br>
 <iframe src=3D"cid:frame1@foo.bar"></iframe><br>
 <iframe src=3D"cid:frame2@foo.bar"></iframe><br>
-And a red square:<br>
-<img src=3D"cid:redsquare@foo.bar">
+<div style=3D"will-change:transform">And a red square:<br>
+<img src=3D"cid:redsquare@foo.bar"></div>
 </body></html>
 ------=_NextPart_000_0000_58874EE0.2096A571
 Content-Type: text/html; charset="ISO-8859-1"

third_party/blink/web_tests/mhtml/multi_frames_ie-expected.html

@@ -3,11 +3,16 @@
 
 
 <title>A page that contains multiple nested frames</title>
+<script>
+  if (window.internals) {
+    internals.settings.setPreferCompositingToLCDTextEnabled(true);
+  }
+</script>
 </head><body>
 This page contains several frames.<br>
-<iframe src="resources/frame_0.html"></iframe><br>
-<iframe src="resources/frame_1.html"></iframe><br>
+<iframe sandbox src="resources/frame_0.html"></iframe><br>
+<iframe sandbox src="resources/frame_1.html"></iframe><br>
 <iframe src="resources/frame_2.html"></iframe><br>
-And a red square:<br>
-<img src="resources/red_square.png">
+<div style="will-change:transform">And a red square:<br>
+<img src="resources/red_square.png"></div>
 </body></html>

third_party/blink/web_tests/mhtml/multi_frames_ie.mht

@@ -40,9 +40,10 @@ http-equiv=3DContent-Type>
 <BODY>This page contains several frames.<BR><IFRAME=20
 src=3D"http://localhost/frame_0.html"></IFRAME><BR><IFRAME=20
 src=3D"http://localhost/frame_1.html"></IFRAME><BR><IFRAME=20
-src=3D"http://localhost/frame_2.html"></IFRAME><BR>And a red =
+src=3D"http://localhost/frame_2.html"></IFRAME><BR><DIV=20
+style=3D"will-change:transform">And a red =
 square:<BR><IMG=20
-src=3D"http://localhost/resources/red_square.png">=20
+src=3D"http://localhost/resources/red_square.png"></DIV>=20
 </BODY></HTML>
 
 ------=_NextPart_001_0023_01CC157B.AAC41680

third_party/blink/web_tests/mhtml/multi_frames_unmht-expected.html

@@ -3,11 +3,16 @@
 
 
 <title>A page that contains multiple nested frames</title>
+<script>
+  if (window.internals) {
+    internals.settings.setPreferCompositingToLCDTextEnabled(true);
+  }
+</script>
 </head><body>
 This page contains several frames.<br>
-<iframe src="resources/frame_0.html"></iframe><br>
-<iframe src="resources/frame_1.html"></iframe><br>
+<iframe sandbox src="resources/frame_0.html"></iframe><br>
+<iframe sandbox src="resources/frame_1.html"></iframe><br>
 <iframe src="resources/frame_2.html"></iframe><br>
-And a red square:<br>
-<img src="resources/red_square.png">
+<div style="will-change:transform">And a red square:<br>
+<img src="resources/red_square.png"></div>
 </body></html>

third_party/blink/web_tests/mhtml/multi_frames_unmht.mht

@@ -21,8 +21,8 @@ This page contains several frames.<br>
 <iframe src=3D"http://localhost/frame_0.html"></iframe><br>
 <iframe src=3D"http://localhost/frame_1.html"></iframe><br>
 <iframe src=3D"http://localhost/frame_2.html"></iframe><br>
-And a red square:<br>
-<img src=3D"resources/red_square.png">
+<div style=3D"will-change:transform">And a red square:<br>
+<img src=3D"resources/red_square.png"></div>
 </body></html>
 ------=_NextPart_000_0000_58874EE0.2096A571
 Content-Type: text/html; charset="ISO-8859-1"

third_party/blink/web_tests/scrollingcoordinator/non-fast-scrollable-region-scaled-iframe.html

@@ -21,7 +21,7 @@
     internals.settings.setPreferCompositingToLCDTextEnabled(false);
 </script>
 
-<iframe src="data:text/html;charset=utf-8,<html><body style='width:1000px;height:1000px;'>Should be covered by a green overlay.</body></html>"></iframe>
+<iframe src="resources/large-body.html"></iframe>
 <div id="console"></div>
 <div class="spacer"></div>
 

third_party/blink/web_tests/scrollingcoordinator/non-fast-scrollable-visibility-change.html

@@ -46,7 +46,7 @@
   <div class="to-show container">
   </div>
   <div class="to-hide container">
-    <iframe src="data:text/html;charset=utf-8,<div style='height:1000px; width:1000px; background: linear-gradient(to bottom, red, white);'>">
+    <iframe src="resources/large-div-background-gradient.html">
       This should not be visible.
     </iframe>
   </div>
@@ -150,7 +150,7 @@
       break;
     case 'iframe':
       window.nextStep = nextStep;
-      inner = '<iframe id="iframe" onload="runAfterLayoutAndPaint(window.nextStep)" src="data:text/html;charset=utf-8,<div style=\'height:1000px; width:1000px; background: linear-gradient(to bottom, red, white);\'>This should be covered by a green overlay.</div>"></iframe>';
+      inner = '<iframe id="iframe" onload="runAfterLayoutAndPaint(window.nextStep)" src="resources/large-div-background-gradient.html"></iframe>';
       break;
     }
     container.innerHTML = inner;

third_party/blink/web_tests/scrollingcoordinator/resources/iframe-containing-non-fast-scrollables.html

@@ -40,7 +40,7 @@
   </div>
 </section>
 <section>
-  <iframe src="data:text/html;charset=utf-8,<style>body {height:1000px; width:1000px; background: linear-gradient(to bottom, red, white);}</style>"></iframe>
+  <iframe src="large-body-background-gradient.html"></iframe>
 </section>
 <section>
   <embed type="application/x-webkit-test-webplugin"></embed>

third_party/blink/web_tests/scrollingcoordinator/resources/large-body-background-gradient.html

+<!DOCTYPE html>
+<style>
+  body {
+    height:1000px;
+    width:1000px;
+    background: linear-gradient(to bottom, red, white);
+  }
+</style>
+<body></body>

third_party/blink/web_tests/scrollingcoordinator/resources/large-body.html

+<!DOCTYPE html>
+<style>
+  body {
+    height:1000px;
+    width:1000px;
+  }
+</style>
+<body>Should be covered by a green overlay.</body>

third_party/blink/web_tests/scrollingcoordinator/resources/large-div-background-gradient.html

+<!DOCTYPE html>
+<style>
+  div {
+    height:1000px;
+    width:1000px;
+    background: linear-gradient(to bottom, red, white);
+  }
+</style>
+<body><div>Should be covered by a green overlay.</div></body>