Remove some internals.layerTreeAsText flags

These flags were used just for a few tests for checking internal data
of composited layers. We should check them with unit tests.

Removed tests:
- compositing/layer-tree.html: just tested LAYER_TREE_INCLUDES_ROOT_LAYER
  which is not important.
- compositing/overflow/composited-scrolling-paint-phases and
  compositing/update-paint-phases.html: The tested functionality is
  already tested by unit test
  CompositedLayerMappingTest.ScrollingContentsAndForegroundLayerPaintingPhase
- compositing/animation/hidden-composited.html: now tested with unit test
  CompositedLayerMappingTest.CompositedHiddenAnimatingLayer.

Change-Id: I148b4480020b41f241cd7ab854c31f96528cf89b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1927187Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#717682}

third_party/blink/renderer/core/frame/local_frame.cc

@@ -824,7 +824,7 @@ String LocalFrame::GetLayerTreeAsTextForTesting(unsigned flags) const {
   } else {
     if (const auto* root_layer =
             ContentLayoutObject()->Compositor()->RootGraphicsLayer()) {
-      if (flags & kLayerTreeIncludesRootLayer && IsMainFrame()) {
+      if (flags & kLayerTreeIncludesAllLayers && IsMainFrame()) {
         while (root_layer->Parent())
           root_layer = root_layer->Parent();
       }

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

@@ -18,6 +18,9 @@
 
 namespace blink {
 
+// TODO(wangxianzhu): Though these tests don't directly apply in
+// CompositeAfterPaint, we should ensure the cases are tested in
+// CompositeAfterPaint mode if applicable.
 class CompositedLayerMappingTest : public RenderingTest {
  public:
   CompositedLayerMappingTest()
@@ -999,12 +1002,12 @@ TEST_F(CompositedLayerMappingTest,
       true);
   SetBodyInnerHTML(R"HTML(
     <div id='container' style='position: relative; z-index: 1; overflow:
-    scroll; width: 300px; height: 300px'>
-        <div id='negative-composited-child' style='background-color: red;
-    width: 1px; height: 1px; position: absolute; backface-visibility:
-    hidden; z-index: -1'></div>
-        <div style='background-color: blue; width: 2000px; height: 2000px;
-    position: relative; top: 10px'></div>
+                               scroll; width: 300px; height: 300px'>
+      <div id='negative-composited-child' style='background-color: red;
+               width: 1px; height: 1px; position: absolute;
+               backface-visibility: hidden; z-index: -1'></div>
+      <div style='background-color: blue; width: 2000px; height: 2000px;
+                  position: relative; top: 10px'></div>
     </div>
   )HTML");
 
@@ -1513,8 +1516,6 @@ TEST_F(CompositedLayerMappingTest, ScrollLayerSizingSubpixelAccumulation) {
 }
 
 TEST_F(CompositedLayerMappingTest, SquashingScroll) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
   SetHtmlInnerHTML(R"HTML(
     <style>
       * { margin: 0 }
@@ -1536,8 +1537,6 @@ TEST_F(CompositedLayerMappingTest, SquashingScroll) {
 }
 
 TEST_F(CompositedLayerMappingTest, SquashingScrollInterestRect) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
   SetHtmlInnerHTML(R"HTML(
     <style>
       * { margin: 0 }
@@ -1562,9 +1561,6 @@ TEST_F(CompositedLayerMappingTest, SquashingScrollInterestRect) {
 
 TEST_F(CompositedLayerMappingTest,
        SquashingBoundsUnderCompositedScrollingWithTransform) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
-
   SetHtmlInnerHTML(R"HTML(
     <div id=scroller style="will-change: transform; overflow: scroll;
         width: 200px; height: 400px;">
@@ -1597,9 +1593,6 @@ TEST_F(CompositedLayerMappingTest,
 }
 
 TEST_F(CompositedLayerMappingTest, ContentsNotOpaqueWithForegroundLayer) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
-
   SetHtmlInnerHTML(R"HTML(
     <style>
       div {
@@ -1622,9 +1615,6 @@ TEST_F(CompositedLayerMappingTest, ContentsNotOpaqueWithForegroundLayer) {
 }
 
 TEST_F(CompositedLayerMappingTest, EmptyBoundsDoesntDrawContent) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
-
   SetHtmlInnerHTML(R"HTML(
     <style>
       div {
@@ -1644,9 +1634,6 @@ TEST_F(CompositedLayerMappingTest, EmptyBoundsDoesntDrawContent) {
 }
 
 TEST_F(CompositedLayerMappingTest, TouchActionRectsWithoutContent) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
-
   SetBodyInnerHTML(
       "<div id='target' style='will-change: transform; width: 100px;"
       "    height: 100px; touch-action: none;'></div>");
@@ -1666,9 +1653,6 @@ TEST_F(CompositedLayerMappingTest, TouchActionRectsWithoutContent) {
 }
 
 TEST_F(CompositedLayerMappingTest, ContentsOpaque) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
-
   SetHtmlInnerHTML(R"HTML(
     <style>
       div {
@@ -1690,9 +1674,6 @@ TEST_F(CompositedLayerMappingTest, ContentsOpaque) {
 }
 
 TEST_F(CompositedLayerMappingTest, NullOverflowControlsHostLayer) {
-  if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled())
-    return;
-
   SetHtmlInnerHTML("<div id='target' style='will-change: transform'></div>");
   CompositedLayerMapping* mapping =
       ToLayoutBoxModelObject(GetLayoutObjectByElementId("target"))
@@ -1701,4 +1682,43 @@ TEST_F(CompositedLayerMappingTest, NullOverflowControlsHostLayer) {
   EXPECT_FALSE(mapping->DetachLayerForOverflowControls());
 }
 
+TEST_F(CompositedLayerMappingTest, CompositedHiddenAnimatingLayer) {
+  SetHtmlInnerHTML(R"HTML(
+    <style>
+    @keyframes slide {
+      0% { transform: translate3d(0px, 0px, 0px); }
+      100% { transform: translate3d(100px, 0px, 1px); }
+    }
+
+    div {
+      width: 123px;
+      height: 234px;
+      animation-duration: 2s;
+      animation-name: slide;
+      animation-iteration-count: infinite;
+      animation-direction: alternate;
+    }
+    </style>
+    <div id="animated"></div>
+  )HTML");
+
+  PaintLayer* animated =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("animated"))->Layer();
+  CompositedLayerMapping* mapping = animated->GetCompositedLayerMapping();
+  ASSERT_TRUE(mapping);
+  EXPECT_TRUE(mapping->MainGraphicsLayer()->GetCompositingReasons() &
+              CompositingReason::kActiveTransformAnimation);
+
+  // We still composite the animated layer even if visibility: hidden.
+  // TODO(crbug.com/937573): Is this necessary?
+  GetDocument()
+      .getElementById("animated")
+      ->setAttribute(html_names::kStyleAttr, "visibility: hidden");
+  UpdateAllLifecyclePhasesForTest();
+  mapping = animated->GetCompositedLayerMapping();
+  ASSERT_TRUE(mapping);
+  EXPECT_TRUE(mapping->MainGraphicsLayer()->GetCompositingReasons() &
+              CompositingReason::kActiveTransformAnimation);
+}
+
 }  // namespace blink

third_party/blink/renderer/core/testing/internals.idl

@@ -190,14 +190,10 @@
     readonly attribute InternalRuntimeFlags runtimeFlags;
     readonly attribute unsigned long workerThreadCount;
 
-    // Flags for layerTreeAsText.
-    // The values of these constants must be kept in sync with the values of LayerTreeFlags in layers_as_json.h.
-    const unsigned short LAYER_TREE_INCLUDES_DEBUG_INFO = 1;
+    // Flag for layerTreeAsText.
+    // The value must be kept in sync with the value of LayerTreeFlags in layers_as_json.h.
+    // Other flags in LayerTreeFlags are not supported in internals API.
     const unsigned short LAYER_TREE_INCLUDES_PAINT_INVALIDATIONS = 2;
-    const unsigned short LAYER_TREE_INCLUDES_PAINTING_PHASES = 4;
-    const unsigned short LAYER_TREE_INCLUDES_ROOT_LAYER = 8;
-    const unsigned short LAYER_TREE_INCLUDES_COMPOSITING_REASONS = 32;
-    const unsigned short LAYER_TREE_INCLUDES_PAINT_RECORDS = 64;
 
     [RaisesException] DOMString layerTreeAsText(Document document, optional unsigned short flags);
 

third_party/blink/renderer/platform/graphics/compositing/layers_as_json.cc

@@ -130,10 +130,12 @@ void LayersAsJSON::AddLayer(const cc::Layer& layer,
                             const FloatPoint& offset,
                             const TransformPaintPropertyNode& transform,
                             const LayerAsJSONClient* json_client) {
-  auto layer_json = CCLayerAsJSON(&layer, Flags(), offset);
+  if (!(flags_ & kLayerTreeIncludesAllLayers) && !layer.DrawsContent())
+    return;
+
+  auto layer_json = CCLayerAsJSON(&layer, flags_, offset);
   if (json_client) {
-    json_client->AppendAdditionalInfoAsJSON(Flags(), layer,
-                                            *(layer_json.get()));
+    json_client->AppendAdditionalInfoAsJSON(flags_, layer, *(layer_json.get()));
   }
   int transform_id = AddTransformJSON(transform);
   if (transform_id)

third_party/blink/renderer/platform/graphics/compositing/layers_as_json.h

@@ -29,7 +29,7 @@ enum {
   kLayerTreeIncludesDebugInfo = 1 << 0,
   kLayerTreeIncludesPaintInvalidations = 1 << 1,
   kLayerTreeIncludesPaintingPhases = 1 << 2,
-  kLayerTreeIncludesRootLayer = 1 << 3,
+  kLayerTreeIncludesAllLayers = 1 << 3,
   kLayerTreeIncludesCompositingReasons = 1 << 5,
   kLayerTreeIncludesPaintRecords = 1 << 6,
   // Outputs all layers as a layer tree. The default is output children
@@ -49,8 +49,6 @@ class PLATFORM_EXPORT LayersAsJSON {
  public:
   LayersAsJSON(LayerTreeFlags);
 
-  LayerTreeFlags Flags() const { return flags_; }
-
   void AddLayer(const cc::Layer& layer,
                 const FloatPoint& offset,
                 const TransformPaintPropertyNode& transform,

third_party/blink/renderer/platform/graphics/compositing/paint_artifact_compositor.cc

@@ -83,11 +83,7 @@ std::unique_ptr<JSONObject> PaintArtifactCompositor::GetLayersAsJSON(
          paint_artifact);
   LayersAsJSON layers_as_json(flags);
   if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled()) {
-    if (!tracks_raster_invalidations_)
-      flags &= ~kLayerTreeIncludesPaintInvalidations;
     for (const auto& layer : root_layer_->children()) {
-      if (!layer->DrawsContent() && !(flags & kLayerTreeIncludesRootLayer))
-        continue;
       const LayerAsJSONClient* json_client = nullptr;
       const TransformPaintPropertyNode* transform = nullptr;
       for (const auto& client : content_layer_clients_) {
@@ -120,12 +116,10 @@ std::unique_ptr<JSONObject> PaintArtifactCompositor::GetLayersAsJSON(
       const auto& foreign_layer_display_item =
           static_cast<const ForeignLayerDisplayItem&>(display_item);
       cc::Layer* layer = foreign_layer_display_item.GetLayer();
-      if ((layer->DrawsContent()) || (flags & kLayerTreeIncludesRootLayer)) {
-        layers_as_json.AddLayer(
-            *layer, foreign_layer_display_item.Offset(),
-            paint_chunk.properties.Transform(),
-            foreign_layer_display_item.GetLayerAsJSONClient());
-      }
+      layers_as_json.AddLayer(
+          *layer, foreign_layer_display_item.Offset(),
+          paint_chunk.properties.Transform(),
+          foreign_layer_display_item.GetLayerAsJSONClient());
     }
   }
   return layers_as_json.Finalize();

third_party/blink/web_tests/compositing/animation/hidden-composited-expected.txt

-Verifies hidden, compositor-animated layers still get composited
-
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
-
-PASS successfullyParsed is true
-
-TEST COMPLETE
-
-PASS hiddenLayerIsComposited(documentLayerTree) is true

third_party/blink/web_tests/compositing/animation/hidden-composited.html

-<!DOCTYPE HTML>
-<style>
-@keyframes slide {
-  0% { transform: translate3d(0px, 0px, 0px); }
-  100% { transform: translate3d(100px, 0px, 1px); }
-}
-
-div {
-  width: 100px;
-  height: 100px;
-  background: green;
-  animation-duration: 2s;
-  animation-name: slide;
-  animation-iteration-count: infinite;
-  animation-direction: alternate;
-}
-</style>
-<div id="animated"></div>
-<script src='../../resources/js-test.js'></script>
-
-<script>
-description('Verifies hidden, compositor-animated layers still get composited');
-
-if (window.internals)
-  internals.settings.setPreferCompositingToLCDTextEnabled(true);
-
-function hiddenLayerIsComposited(layers) {
-  var found = false;
-  layers["layers"].forEach(function(layer) {
-    if (layer.bounds[0] == 100 && layer.bounds[1] == 100) {
-      for (var j = 0; j < layer.compositingReasons.length; j++) {
-        if (layer.compositingReasons[j].includes('active accelerated transform animation'))
-          found = true;
-      }
-    }
-  });
-  return found;
-}
-
-onload = function() {
-  if (!window.internals)
-    return;
-
-  document.getElementById('animated').style.visibility = 'hidden';
-  internals.forceCompositingUpdate(document);
-
-  documentLayerTree = JSON.parse(internals.layerTreeAsText(
-      document, window.internals.LAYER_TREE_INCLUDES_COMPOSITING_REASONS));
-
-  shouldBe('hiddenLayerIsComposited(documentLayerTree)', 'true');
-};
-</script>

third_party/blink/web_tests/compositing/layer-tree-expected.txt

-Layer list
-{
-  "layers": [
-    {
-      "name": "Inner Viewport Scroll Layer",
-      "bounds": [800, 600],
-      "drawsContent": false
-    },
-    {
-      "name": "LayoutView #document",
-      "bounds": [800, 600],
-      "drawsContent": false,
-      "backgroundColor": "#FFFFFF"
-    },
-    {
-      "name": "Scrolling Contents Layer",
-      "bounds": [1200, 900],
-      "contentsOpaque": true,
-      "backgroundColor": "#FFFFFF"
-    },
-    {
-      "name": "Horizontal Scrollbar Layer",
-      "position": [0, 580],
-      "bounds": [780, 20]
-    },
-    {
-      "name": "Vertical Scrollbar Layer",
-      "position": [780, 0],
-      "bounds": [20, 580]
-    },
-    {
-      "name": "Scroll Corner Layer",
-      "position": [780, 580],
-      "bounds": [20, 20]
-    }
-  ]
-}
-

third_party/blink/web_tests/compositing/layer-tree.html

-<!DOCTYPE html>
-<!--
-This test dumps the full composited layer tree on a blank page with overflow.
--->
-<style>
-html { overflow: scroll; width: 1200px; height: 900px; }
-/* Fixed scrollbar thickness for consistency across platforms. */
-::-webkit-scrollbar { width: 20px; height: 20px; }
-::-webkit-scrollbar-thumb { background-color: blue; }
-</style>
-<script>
-
-testRunner.dumpAsText();
-testRunner.setCustomTextOutput(
-  "Layer list\n" +
-  internals.layerTreeAsText(document,
-    internals.LAYER_TREE_INCLUDES_ROOT_LAYER));
-</script>

third_party/blink/web_tests/compositing/overflow/composited-scrolling-paint-phases-expected.txt

-{
-  "layers": [
-    {
-      "name": "LayoutNGBlockFlow HTML",
-      "bounds": [800, 242],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ]
-    },
-    {
-      "name": "LayoutNGBlockFlow (relative positioned) DIV class='composited'",
-      "bounds": [80, 10],
-      "contentsOpaque": true,
-      "backgroundColor": "#008000",
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 2
-    },
-    {
-      "name": "LayoutNGBlockFlow HTML (foreground) Layer",
-      "bounds": [800, 242],
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground"
-      ]
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='container'",
-      "bounds": [202, 202],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintCompositedScroll",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "Scrolling Contents Layer",
-      "position": [1, 1],
-      "bounds": [185, 715],
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintOverflowContents",
-        "GraphicsLayerPaintCompositedScroll"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Horizontal Scrollbar Layer",
-      "position": [1, 186],
-      "bounds": [185, 15],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Vertical Scrollbar Layer",
-      "position": [186, 1],
-      "bounds": [15, 185],
-      "transform": 1
-    },
-    {
-      "name": "Scroll Corner Layer",
-      "position": [186, 186],
-      "bounds": [15, 15],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [28, 20, 0, 1]
-      ]
-    },
-    {
-      "id": 2,
-      "parent": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [1, 11, 0, 1]
-      ]
-    }
-  ]
-}
-
-

third_party/blink/web_tests/compositing/overflow/composited-scrolling-paint-phases.html

-<!DOCTYPE html>
-<html lang="en">
-<head>
-  <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
-  <title>Composited scrolling paint phases</title>
-  <style type="text/css" media="screen">
-    .container {
-      width: 200px;
-      height: 200px;
-      overflow: scroll;
-      margin: 20px;
-      border: 1px solid black;
-    }
-
-    .composited {
-      width: 80px;
-      height: 10px;
-      position: relative;
-      top: 10px;
-      will-change: transform;
-      background-color: green;
-      z-index: -1;
-    }
-
-    .not-composited {
-      width: 80px;
-      height: 20px;
-      margin: 5px;
-      background-color: blue;
-    }
-  </style>
-  <script>
-    if (window.testRunner)
-      testRunner.dumpAsText();
-
-    if (window.internals)
-      internals.settings.setPreferCompositingToLCDTextEnabled(true);
-
-    function write(str)
-    {
-      var pre = document.getElementById('console');
-      var text = document.createTextNode(str + '\n');
-      pre.appendChild(text);
-    }
-
-    function doTest()
-    {
-      write(internals.layerTreeAsText(document, window.internals.LAYER_TREE_INCLUDES_PAINTING_PHASES));
-      if (window.testRunner)
-        testRunner.notifyDone(); 
-    }
-
-    window.addEventListener('load', doTest, false);
-
-    if (window.testRunner)
-      testRunner.waitUntilDone();
-  </script>
-</head>
-<body>
-  <div class="container">
-    <div class="composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-    <div class="not-composited"></div>
-  </div>
-  <pre id="console"></pre>
-</body>
-</html>
-

third_party/blink/web_tests/compositing/update-paint-phases-expected.txt

-{
-  "layers": [
-    {
-      "name": "Scrolling Contents Layer",
-      "bounds": [800, 600],
-      "contentsOpaque": true,
-      "backgroundColor": "#FFFFFF",
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintOverflowContents",
-        "GraphicsLayerPaintCompositedScroll"
-      ]
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='scroller'",
-      "bounds": [102, 102],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintCompositedScroll",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "Scrolling Contents Layer",
-      "position": [1, 1],
-      "bounds": [85, 120],
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintOverflowContents",
-        "GraphicsLayerPaintCompositedScroll"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Horizontal Scrollbar Layer",
-      "position": [1, 86],
-      "bounds": [85, 15],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Vertical Scrollbar Layer",
-      "position": [86, 1],
-      "bounds": [15, 85],
-      "transform": 1
-    },
-    {
-      "name": "Scroll Corner Layer",
-      "position": [86, 86],
-      "bounds": [15, 15],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [8, 8, 0, 1]
-      ]
-    }
-  ]
-}
-

third_party/blink/web_tests/compositing/update-paint-phases.html

-<!DOCTYPE HTML>
-<style>
-.scroller {
-    width: 100px;
-    height: 100px;
-    border: 1px solid black;
-    overflow: scroll;
-}
-
-.scrolled {
-    width: 40px;
-    height: 40px;
-    background: green;
-}
-
-.neg-zorder {
-    position: relative;
-    z-index: -1;
-    will-change: transform;
-    background: blue;
-}
-</style>
-<script>
-    if (window.internals) {
-        internals.settings.setPreferCompositingToLCDTextEnabled(true);
-    }
-</script>
-<div class="scroller">
-    <div class="scrolled neg-zorder" id="to-modify"></div>
-    <div class="scrolled"></div>
-    <div class="scrolled"></div>
-    <div class="scrolled"></div>
-</div>
-<script>
-    if (window.testRunner)
-        testRunner.dumpAsText();
-
-    if (window.internals) {
-        internals.forceCompositingUpdate(document);
-        internals.startTrackingRepaints(document);
-    }
-
-    document.querySelector('style').appendChild(document.createTextNode('#to-modify { display: none }'));
-
-    if (window.internals) {
-        var layerTree = document.createElement('pre');
-        layerTree.innerHTML = internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_PAINTING_PHASES); 
-        internals.stopTrackingRepaints(document);
-        document.body.appendChild(layerTree);
-    }
-</script>

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/layer-tree-expected.txt

-Layer list
-{
-  "layers": [
-    {
-      "name": "LayoutView #document",
-      "bounds": [780, 580],
-      "drawsContent": false
-    },
-    {
-      "name": "Scrolling background of LayoutView #document",
-      "bounds": [1200, 900],
-      "contentsOpaque": true,
-      "backgroundColor": "#FFFFFF"
-    },
-    {
-      "name": "LayoutCustomScrollbarPart (anonymous)",
-      "bounds": [800, 600],
-      "backgroundColor": "#0000FF"
-    }
-  ]
-}
-

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/overflow/composited-scrolling-paint-phases-expected.txt

-{
-  "layers": [
-    {
-      "name": "Scrolling background of LayoutView #document",
-      "bounds": [800, 600],
-      "contentsOpaque": true,
-      "backgroundColor": "#FFFFFF"
-    },
-    {
-      "name": "LayoutNGBlockFlow (relative positioned) DIV class='composited'",
-      "bounds": [80, 10],
-      "contentsOpaque": true,
-      "backgroundColor": "#008000",
-      "transform": 2
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='container'",
-      "bounds": [202, 202],
-      "transform": 1
-    },
-    {
-      "name": "HorizontalScrollbar",
-      "position": [1, 186],
-      "bounds": [185, 15],
-      "transform": 1
-    },
-    {
-      "name": "VerticalScrollbar",
-      "position": [186, 1],
-      "bounds": [15, 185],
-      "transform": 1
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='container'",
-      "bounds": [202, 202],
-      "transform": 1
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='container'",
-      "position": [6, 16],
-      "bounds": [80, 695],
-      "backgroundColor": "#0000FF",
-      "transform": 1
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [28, 20, 0, 1]
-      ]
-    },
-    {
-      "id": 2,
-      "parent": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [1, 11, 0, 1]
-      ]
-    }
-  ]
-}
-
-

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/update-paint-phases-expected.txt

-{
-  "layers": [
-    {
-      "name": "Scrolling background of LayoutView #document",
-      "bounds": [800, 600],
-      "contentsOpaque": true,
-      "backgroundColor": "#FFFFFF"
-    },
-    {
-      "name": "HorizontalScrollbar",
-      "position": [1, 86],
-      "bounds": [85, 15],
-      "transform": 1
-    },
-    {
-      "name": "VerticalScrollbar",
-      "position": [86, 1],
-      "bounds": [15, 85],
-      "transform": 1
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='scroller'",
-      "bounds": [102, 102],
-      "transform": 1
-    },
-    {
-      "name": "LayoutNGBlockFlow DIV class='scroller'",
-      "position": [1, 1],
-      "bounds": [40, 120],
-      "contentsOpaque": true,
-      "backgroundColor": "#008000",
-      "transform": 1
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [8, 8, 0, 1]
-      ]
-    }
-  ]
-}
-

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/overflow/composited-scrolling-paint-phases-expected.txt

-{
-  "layers": [
-    {
-      "name": "LayoutBlockFlow HTML",
-      "bounds": [800, 242],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ]
-    },
-    {
-      "name": "LayoutBlockFlow (relative positioned) DIV class='composited'",
-      "bounds": [80, 10],
-      "contentsOpaque": true,
-      "backgroundColor": "#008000",
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 2
-    },
-    {
-      "name": "LayoutBlockFlow HTML (foreground) Layer",
-      "bounds": [800, 242],
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground"
-      ]
-    },
-    {
-      "name": "LayoutBlockFlow DIV class='container'",
-      "bounds": [202, 202],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintCompositedScroll",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "Scrolling Contents Layer",
-      "position": [1, 1],
-      "bounds": [185, 715],
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintOverflowContents",
-        "GraphicsLayerPaintCompositedScroll"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Horizontal Scrollbar Layer",
-      "position": [1, 186],
-      "bounds": [185, 15],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Vertical Scrollbar Layer",
-      "position": [186, 1],
-      "bounds": [15, 185],
-      "transform": 1
-    },
-    {
-      "name": "Scroll Corner Layer",
-      "position": [186, 186],
-      "bounds": [15, 15],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [28, 20, 0, 1]
-      ]
-    },
-    {
-      "id": 2,
-      "parent": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [1, 11, 0, 1]
-      ]
-    }
-  ]
-}
-
-

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/update-paint-phases-expected.txt

-{
-  "layers": [
-    {
-      "name": "Scrolling Contents Layer",
-      "bounds": [800, 600],
-      "contentsOpaque": true,
-      "backgroundColor": "#FFFFFF",
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintOverflowContents",
-        "GraphicsLayerPaintCompositedScroll"
-      ]
-    },
-    {
-      "name": "LayoutBlockFlow DIV class='scroller'",
-      "bounds": [102, 102],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintCompositedScroll",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "Scrolling Contents Layer",
-      "position": [1, 1],
-      "bounds": [85, 120],
-      "paintingPhases": [
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintOverflowContents",
-        "GraphicsLayerPaintCompositedScroll"
-      ],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Horizontal Scrollbar Layer",
-      "position": [1, 86],
-      "bounds": [85, 15],
-      "transform": 1
-    },
-    {
-      "name": "ContentsLayer for Vertical Scrollbar Layer",
-      "position": [86, 1],
-      "bounds": [15, 85],
-      "transform": 1
-    },
-    {
-      "name": "Scroll Corner Layer",
-      "position": [86, 86],
-      "bounds": [15, 15],
-      "paintingPhases": [
-        "GraphicsLayerPaintBackground",
-        "GraphicsLayerPaintForeground",
-        "GraphicsLayerPaintMask",
-        "GraphicsLayerPaintDecoration"
-      ],
-      "transform": 1
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [8, 8, 0, 1]
-      ]
-    }
-  ]
-}
-