Remove the ClipsCompositingDescendants compositing reason

We no longer need to composite for clipping because the clip can be
applied in the compositor via property trees.

Change-Id: I740cd8e7b247a7f8bcd98562daedaeef7f1efca3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2235638
Commit-Queue: Philip Rogers <pdr@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#777524}

third_party/blink/renderer/core/css/style_engine.cc

@@ -2061,15 +2061,6 @@ void StyleEngine::ViewportDefiningElementDidChange() {
     // ViewportDefiningElement changes in order to trigger an update of
     // HasOverflowClip() and the PaintLayer in StyleDidChange().
     layout_object->SetStyle(ComputedStyle::Clone(*layout_object->Style()));
-    // CompositingReason::kClipsCompositingDescendants depends on the root
-    // element having a clip-related style. Since style update due to changes of
-    // viewport-defining element don't end up as a StyleDifference, we need a
-    // special dirty bit for this situation.
-    if (layout_object->HasLayer()) {
-      ToLayoutBoxModelObject(layout_object)
-          ->Layer()
-          ->SetNeedsCompositingReasonsUpdate();
-    }
   }
 }
 

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

@@ -81,9 +81,6 @@ CompositingReasonFinder::PotentialCompositingReasonsFromStyle(
   if (layout_object.HasReflection())
     reasons |= CompositingReason::kReflectionWithCompositedDescendants;
 
-  if (layout_object.HasClipRelatedProperty())
-    reasons |= CompositingReason::kClipsCompositingDescendants;
-
   DCHECK(!(reasons & ~CompositingReason::kComboAllStyleDeterminedReasons));
   return reasons;
 }

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

@@ -590,17 +590,11 @@ void CompositingRequirementsUpdater::UpdateRecursive(
       current_recursion_data.subtree_is_compositing_ = true;
 
     // Turn overlap testing off for later layers if it's already off, or if we
-    // have an animating transform.  Note that if the layer clips its
-    // descendants, there's no reason to propagate the child animation to the
-    // parent layers. That's because we know for sure the animation is contained
-    // inside the clipping rectangle, which is already added to the overlap map.
-    bool is_composited_clipping_layer =
-        can_be_composited && (reasons_to_composite &
-                              CompositingReason::kClipsCompositingDescendants);
-    if ((!child_recursion_data.testing_overlap_ &&
-         !is_composited_clipping_layer) ||
-        layer->GetLayoutObject().StyleRef().HasCurrentTransformAnimation())
+    // have an animating transform.
+    if (!child_recursion_data.testing_overlap_ ||
+        layer->GetLayoutObject().StyleRef().HasCurrentTransformAnimation()) {
       current_recursion_data.testing_overlap_ = false;
+    }
 
     if (child_recursion_data.compositing_ancestor_ == layer ||
         contains_composited_layer) {

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

@@ -54,33 +54,6 @@ TEST_F(CompositingRequirementsUpdaterTest,
   EXPECT_EQ(CompositingReason::kOverlap, target->GetCompositingReasons());
 }
 
-TEST_F(CompositingRequirementsUpdaterTest,
-       NoDescendantReasonForNonSelfPaintingLayer) {
-  SetBodyInnerHTML(R"HTML(
-    <style>
-      #target {
-        overflow: auto;
-        width: 100px;
-        height: 100px;
-      }
-    </style>
-    <div id=target>
-      <div style="backface-visibility: hidden"></div>
-    </div>
-  )HTML");
-
-  PaintLayer* target =
-      ToLayoutBoxModelObject(GetLayoutObjectByElementId("target"))->Layer();
-  EXPECT_FALSE(target->GetCompositingReasons());
-
-  // Now make |target| self-painting.
-  GetDocument().getElementById("target")->setAttribute(html_names::kStyleAttr,
-                                                       "position: relative");
-  UpdateAllLifecyclePhasesForTest();
-  EXPECT_EQ(CompositingReason::kClipsCompositingDescendants,
-            target->GetCompositingReasons());
-}
-
 // This test sets up a situation where a squashed PaintLayer loses its
 // backing, but does not change visual rect. Therefore the compositing system
 // must invalidate it because of change of backing.

third_party/blink/renderer/platform/graphics/compositing_reasons.cc

@@ -90,10 +90,6 @@ constexpr CompositingReasonStringMap kCompositingReasonsStringMap[] = {
      "blendingWithCompositedDescendants",
      "Has a blending effect that needs to be known by compositor because of "
      "composited descendants"},
-    {CompositingReason::kClipsCompositingDescendants,
-     "clipsCompositingDescendants",
-     "Has a clip that needs to be known by compositor because of composited "
-     "descendants"},
     {CompositingReason::kPerspectiveWith3DDescendants,
      "perspectiveWith3DDescendants",
      "Has a perspective transform that needs to be known by compositor because "

third_party/blink/renderer/platform/graphics/compositing_reasons.h

@@ -59,7 +59,6 @@ using CompositingReasons = uint64_t;
   V(ReflectionWithCompositedDescendants)                                      \
   V(FilterWithCompositedDescendants)                                          \
   V(BlendingWithCompositedDescendants)                                        \
-  V(ClipsCompositingDescendants)                                              \
   V(PerspectiveWith3DDescendants)                                             \
   V(Preserve3DWith3DDescendants)                                              \
   V(IsolateCompositedDescendants)                                             \
@@ -142,7 +141,7 @@ class PLATFORM_EXPORT CompositingReason {
         kIsolateCompositedDescendants | kOpacityWithCompositedDescendants |
         kMaskWithCompositedDescendants | kFilterWithCompositedDescendants |
         kBlendingWithCompositedDescendants |
-        kReflectionWithCompositedDescendants | kClipsCompositingDescendants,
+        kReflectionWithCompositedDescendants,
 
     kCombo3DDescendants =
         kPreserve3DWith3DDescendants | kPerspectiveWith3DDescendants,

third_party/blink/web_tests/compositing/geometry/clip-expected.txt

@@ -15,18 +15,11 @@ Test CSS clip with composited layers. Left and right sides should look the same.
       "backgroundColor": "#808080",
       "transform": 2
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='box'",
-      "bounds": [100, 100],
-      "contentsOpaque": true,
-      "backgroundColor": "#808080",
-      "transform": 3
-    },
     {
       "name": "LayoutNGBlockFlow (relative positioned) DIV class='composited inner'",
       "bounds": [120, 120],
       "backgroundColor": "#00000033",
-      "transform": 5
+      "transform": 4
     }
   ],
   "transforms": [
@@ -55,22 +48,12 @@ Test CSS clip with composited layers. Left and right sides should look the same.
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 20, 0, 1]
+        [210, 10, 0, 1]
       ]
     },
     {
       "id": 4,
       "parent": 3,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [-10, -10, 0, 1]
-      ]
-    },
-    {
-      "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/compositing/geometry/clip-inside-expected.txt

@@ -16,19 +16,11 @@ Test CSS clip with composited layers. Left and right sides should look the same.
       "backgroundColor": "#808080",
       "transform": 2
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='box'",
-      "position": [5, 15],
-      "bounds": [90, 80],
-      "contentsOpaque": true,
-      "backgroundColor": "#808080",
-      "transform": 3
-    },
     {
       "name": "LayoutNGBlockFlow (relative positioned) DIV class='composited inner'",
       "bounds": [120, 120],
       "backgroundColor": "#00000033",
-      "transform": 5
+      "transform": 4
     }
   ],
   "transforms": [
@@ -57,22 +49,12 @@ Test CSS clip with composited layers. Left and right sides should look the same.
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 20, 0, 1]
+        [210, 10, 0, 1]
       ]
     },
     {
       "id": 4,
       "parent": 3,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [-10, -10, 0, 1]
-      ]
-    },
-    {
-      "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/compositing/geometry/clip-with-shadow-expected.txt

@@ -13,18 +13,11 @@
       "backgroundColor": "#808080",
       "transform": 2
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='box'",
-      "position": [-2, -2],
-      "bounds": [106, 106],
-      "backgroundColor": "#808080",
-      "transform": 3
-    },
     {
       "name": "LayoutNGBlockFlow (relative positioned) DIV class='composited inner'",
       "bounds": [120, 120],
       "backgroundColor": "#00000033",
-      "transform": 5
+      "transform": 4
     }
   ],
   "transforms": [
@@ -53,22 +46,12 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 20, 0, 1]
+        [210, 10, 0, 1]
       ]
     },
     {
       "id": 4,
       "parent": 3,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [-10, -10, 0, 1]
-      ]
-    },
-    {
-      "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/compositing/layer-creation/overlap-animation-expected.txt

@@ -6,25 +6,26 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (relative positioned) DIV class='container'",
-      "bounds": [122, 242],
-      "transform": 1
-    },
     {
       "name": "LayoutNGBlockFlow (relative positioned) DIV id='to-animate' class='animating box'",
       "bounds": [100, 100],
       "contentsOpaque": true,
       "backgroundColor": "#0000FF",
-      "transform": 3
+      "transform": 2
     },
     {
       "name": "LayoutNGBlockFlow (relative positioned) DIV class='box'",
-      "position": [11, 121],
+      "position": [19, 129],
       "bounds": [100, 100],
       "contentsOpaque": true,
-      "backgroundColor": "#0000FF",
-      "transform": 1
+      "backgroundColor": "#0000FF"
+    },
+    {
+      "name": "LayoutNGBlockFlow (relative positioned) DIV class='box'",
+      "position": [18, 260],
+      "bounds": [100, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#0000FF"
     }
   ],
   "transforms": [
@@ -40,16 +41,6 @@
     {
       "id": 2,
       "parent": 1,
-      "transform": [
-        [...],
-        [...],
-        [...],
-        [...]
-      ]
-    },
-    {
-      "id": 3,
-      "parent": 2,
       "transform": [
         [...],
         [...],

third_party/blink/web_tests/compositing/layer-creation/overlap-transformed-and-clipped-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='container clips'",
-      "bounds": [100, 100],
-      "transform": 1
-    },
     {
       "name": "LayoutNGBlockFlow (positioned) DIV class='under composited'",
       "bounds": [100, 100],

third_party/blink/web_tests/compositing/layer-creation/overlap-transforms-expected.txt

@@ -6,17 +6,12 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (relative positioned) DIV class='container'",
-      "bounds": [122, 242],
-      "transform": 1
-    },
     {
       "name": "LayoutNGBlockFlow (relative positioned) DIV class='transformed box'",
       "bounds": [100, 100],
       "contentsOpaque": true,
       "backgroundColor": "#0000FF",
-      "transform": 3
+      "transform": 2
     }
   ],
   "transforms": [
@@ -26,22 +21,12 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [8, 8, 0, 1]
+        [19, 19, 0, 1]
       ]
     },
     {
       "id": 2,
       "parent": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [11, 11, 0, 1]
-      ]
-    },
-    {
-      "id": 3,
-      "parent": 2,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/compositing/overflow/clip-descendents-expected.txt

@@ -6,57 +6,33 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 1
-    },
     {
       "name": "LayoutNGBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 3
-    },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 4
+      "transform": 2
     },
     {
       "name": "LayoutNGBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 6
-    },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 7
+      "transform": 4
     },
     {
       "name": "LayoutNGBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 9
-    },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 10
+      "transform": 6
     },
     {
       "name": "LayoutNGBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 12
+      "transform": 8
     }
   ],
   "transforms": [
@@ -66,7 +42,7 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [28, 28, 0, 1]
+        [50, 50, 0, 1]
       ]
     },
     {
@@ -76,36 +52,35 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [22, 22, 0, 1]
+        [0, 0, 1, 1]
       ]
     },
     {
       "id": 3,
-      "parent": 2,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [0, 0, 1, 1]
+        [242, 50, 0, 1]
       ]
     },
     {
       "id": 4,
+      "parent": 3,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 28, 0, 1]
+        [0, 0, 1, 1]
       ]
     },
     {
       "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [22, 22, 0, 1]
+        [50, 242, 0, 1]
       ]
     },
     {
@@ -124,51 +99,12 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [28, 220, 0, 1]
+        [242, 242, 0, 1]
       ]
     },
     {
       "id": 8,
       "parent": 7,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [22, 22, 0, 1]
-      ]
-    },
-    {
-      "id": 9,
-      "parent": 8,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [0, 0, 1, 1]
-      ]
-    },
-    {
-      "id": 10,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [220, 220, 0, 1]
-      ]
-    },
-    {
-      "id": 11,
-      "parent": 10,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [22, 22, 0, 1]
-      ]
-    },
-    {
-      "id": 12,
-      "parent": 11,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/compositing/overflow/reparented-scrollbars-non-sc-anc-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (relative positioned) DIV id='positioned'",
-      "bounds": [1200, 800],
-      "transform": 1
-    },
     {
       "name": "LayoutNGBlockFlow DIV id='scroller'",
       "bounds": [1200, 1000],

third_party/blink/web_tests/compositing/overflow/rotate-clip-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow DIV",
-      "bounds": [240, 240],
-      "transform": 2
-    },
     {
       "name": "LayoutNGBlockFlow DIV",
       "bounds": [400, 400],

third_party/blink/web_tests/compositing/overflow/scrollbar-layer-placement-expected.txt

@@ -90,17 +90,11 @@
       "bounds": [352, 294],
       "transform": 7
     },
-    {
-      "name": "LayoutNGBlockFlow (relative positioned) DIV class='clipper'",
-      "position": [-7, -7],
-      "bounds": [292, 200],
-      "transform": 8
-    },
     {
       "name": "LayoutNGBlockFlow DIV class='scroller'",
       "position": [-30, -30],
       "bounds": [290, 230],
-      "transform": 9
+      "transform": 8
     },
     {
       "name": "Scrolling Contents Layer",
@@ -108,13 +102,13 @@
       "bounds": [220, 236],
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF",
-      "transform": 9
+      "transform": 8
     },
     {
       "name": "ContentsLayer for Vertical Scrollbar Layer",
       "position": [218, 5],
       "bounds": [7, 160],
-      "transform": 9
+      "transform": 8
     }
   ],
   "transforms": [
@@ -191,17 +185,7 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [16, 16, 0, 1]
-      ]
-    },
-    {
-      "id": 9,
-      "parent": 8,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [24, 24, 0, 1]
+        [40, 40, 0, 1]
       ]
     }
   ]

third_party/blink/web_tests/compositing/visibility/layer-visible-content-expected.txt

@@ -6,10 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV class='container'",
-      "bounds": [200, 200]
-    },
     {
       "name": "LayoutNGBlockFlow DIV class='composited box'",
       "bounds": [10, 10],

third_party/blink/web_tests/fast/borders/overflow-hidden-border-radius-force-backing-store-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV id='outer'",
-      "bounds": [300, 300],
-      "transform": 1
-    },
     {
       "name": "LayoutNGBlockFlow DIV id='content'",
       "bounds": [285, 1000],

third_party/blink/web_tests/flag-specific/composite-after-paint/virtual/threaded/compositing/visibility/layer-visible-content-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutNGBlockFlow DIV class='composited box'",
+      "bounds": [10, 10],
+      "drawsContent": false
+    }
+  ]
+}
+

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/geometry/clip-expected.txt

@@ -15,18 +15,11 @@ Test CSS clip with composited layers. Left and right sides should look the same.
       "backgroundColor": "#808080",
       "transform": 2
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='box'",
-      "bounds": [100, 100],
-      "contentsOpaque": true,
-      "backgroundColor": "#808080",
-      "transform": 3
-    },
     {
       "name": "LayoutBlockFlow (relative positioned) DIV class='composited inner'",
       "bounds": [120, 120],
       "backgroundColor": "#00000033",
-      "transform": 5
+      "transform": 4
     }
   ],
   "transforms": [
@@ -55,22 +48,12 @@ Test CSS clip with composited layers. Left and right sides should look the same.
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 20, 0, 1]
+        [210, 10, 0, 1]
       ]
     },
     {
       "id": 4,
       "parent": 3,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [-10, -10, 0, 1]
-      ]
-    },
-    {
-      "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/geometry/clip-inside-expected.txt

@@ -16,19 +16,11 @@ Test CSS clip with composited layers. Left and right sides should look the same.
       "backgroundColor": "#808080",
       "transform": 2
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='box'",
-      "position": [5, 15],
-      "bounds": [90, 80],
-      "contentsOpaque": true,
-      "backgroundColor": "#808080",
-      "transform": 3
-    },
     {
       "name": "LayoutBlockFlow (relative positioned) DIV class='composited inner'",
       "bounds": [120, 120],
       "backgroundColor": "#00000033",
-      "transform": 5
+      "transform": 4
     }
   ],
   "transforms": [
@@ -57,22 +49,12 @@ Test CSS clip with composited layers. Left and right sides should look the same.
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 20, 0, 1]
+        [210, 10, 0, 1]
       ]
     },
     {
       "id": 4,
       "parent": 3,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [-10, -10, 0, 1]
-      ]
-    },
-    {
-      "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/geometry/clip-with-shadow-expected.txt

@@ -13,18 +13,11 @@
       "backgroundColor": "#808080",
       "transform": 2
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='box'",
-      "position": [-2, -2],
-      "bounds": [106, 106],
-      "backgroundColor": "#808080",
-      "transform": 3
-    },
     {
       "name": "LayoutBlockFlow (relative positioned) DIV class='composited inner'",
       "bounds": [120, 120],
       "backgroundColor": "#00000033",
-      "transform": 5
+      "transform": 4
     }
   ],
   "transforms": [
@@ -53,22 +46,12 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 20, 0, 1]
+        [210, 10, 0, 1]
       ]
     },
     {
       "id": 4,
       "parent": 3,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [-10, -10, 0, 1]
-      ]
-    },
-    {
-      "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/layer-creation/overlap-animation-expected.txt

@@ -6,25 +6,26 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (relative positioned) DIV class='container'",
-      "bounds": [122, 242],
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow (relative positioned) DIV id='to-animate' class='animating box'",
       "bounds": [100, 100],
       "contentsOpaque": true,
       "backgroundColor": "#0000FF",
-      "transform": 3
+      "transform": 2
     },
     {
       "name": "LayoutBlockFlow (relative positioned) DIV class='box'",
-      "position": [11, 121],
+      "position": [19, 129],
       "bounds": [100, 100],
       "contentsOpaque": true,
-      "backgroundColor": "#0000FF",
-      "transform": 1
+      "backgroundColor": "#0000FF"
+    },
+    {
+      "name": "LayoutBlockFlow (relative positioned) DIV class='box'",
+      "position": [18, 260],
+      "bounds": [100, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#0000FF"
     }
   ],
   "transforms": [
@@ -40,16 +41,6 @@
     {
       "id": 2,
       "parent": 1,
-      "transform": [
-        [...],
-        [...],
-        [...],
-        [...]
-      ]
-    },
-    {
-      "id": 3,
-      "parent": 2,
       "transform": [
         [...],
         [...],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/layer-creation/overlap-transformed-and-clipped-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='container clips'",
-      "bounds": [100, 100],
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow (positioned) DIV class='under composited'",
       "bounds": [100, 100],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/layer-creation/overlap-transforms-expected.txt

@@ -6,17 +6,12 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (relative positioned) DIV class='container'",
-      "bounds": [122, 242],
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow (relative positioned) DIV class='transformed box'",
       "bounds": [100, 100],
       "contentsOpaque": true,
       "backgroundColor": "#0000FF",
-      "transform": 3
+      "transform": 2
     }
   ],
   "transforms": [
@@ -26,22 +21,12 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [8, 8, 0, 1]
+        [19, 19, 0, 1]
       ]
     },
     {
       "id": 2,
       "parent": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [11, 11, 0, 1]
-      ]
-    },
-    {
-      "id": 3,
-      "parent": 2,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/overflow/clip-descendents-expected.txt

@@ -6,57 +6,33 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 3
-    },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 4
+      "transform": 2
     },
     {
       "name": "LayoutBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 6
-    },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 7
+      "transform": 4
     },
     {
       "name": "LayoutBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 9
-    },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='container'",
-      "position": [20, 10],
-      "bounds": [60, 70],
-      "transform": 10
+      "transform": 6
     },
     {
       "name": "LayoutBlockFlow DIV class='box'",
       "bounds": [100, 150],
       "contentsOpaque": true,
       "backgroundColor": "#808080",
-      "transform": 12
+      "transform": 8
     }
   ],
   "transforms": [
@@ -66,7 +42,7 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [28, 28, 0, 1]
+        [50, 50, 0, 1]
       ]
     },
     {
@@ -76,36 +52,35 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [22, 22, 0, 1]
+        [0, 0, 1, 1]
       ]
     },
     {
       "id": 3,
-      "parent": 2,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [0, 0, 1, 1]
+        [242, 50, 0, 1]
       ]
     },
     {
       "id": 4,
+      "parent": 3,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [220, 28, 0, 1]
+        [0, 0, 1, 1]
       ]
     },
     {
       "id": 5,
-      "parent": 4,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [22, 22, 0, 1]
+        [50, 242, 0, 1]
       ]
     },
     {
@@ -124,51 +99,12 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [28, 220, 0, 1]
+        [242, 242, 0, 1]
       ]
     },
     {
       "id": 8,
       "parent": 7,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [22, 22, 0, 1]
-      ]
-    },
-    {
-      "id": 9,
-      "parent": 8,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [0, 0, 1, 1]
-      ]
-    },
-    {
-      "id": 10,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [220, 220, 0, 1]
-      ]
-    },
-    {
-      "id": 11,
-      "parent": 10,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [22, 22, 0, 1]
-      ]
-    },
-    {
-      "id": 12,
-      "parent": 11,
       "transform": [
         [1, 0, 0, 0],
         [0, 1, 0, 0],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/overflow/reparented-scrollbars-non-sc-anc-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (relative positioned) DIV id='positioned'",
-      "bounds": [1200, 800],
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow DIV id='scroller'",
       "bounds": [1200, 1000],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/overflow/rotate-clip-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow DIV",
-      "bounds": [240, 240],
-      "transform": 2
-    },
     {
       "name": "LayoutBlockFlow DIV",
       "bounds": [400, 400],

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/overflow/scrollbar-layer-placement-expected.txt

@@ -90,17 +90,11 @@
       "bounds": [352, 294],
       "transform": 7
     },
-    {
-      "name": "LayoutBlockFlow (relative positioned) DIV class='clipper'",
-      "position": [-7, -7],
-      "bounds": [292, 200],
-      "transform": 8
-    },
     {
       "name": "LayoutBlockFlow DIV class='scroller'",
       "position": [-30, -30],
       "bounds": [290, 230],
-      "transform": 9
+      "transform": 8
     },
     {
       "name": "Scrolling Contents Layer",
@@ -108,13 +102,13 @@
       "bounds": [220, 236],
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF",
-      "transform": 9
+      "transform": 8
     },
     {
       "name": "ContentsLayer for Vertical Scrollbar Layer",
       "position": [218, 5],
       "bounds": [7, 160],
-      "transform": 9
+      "transform": 8
     }
   ],
   "transforms": [
@@ -191,17 +185,7 @@
         [1, 0, 0, 0],
         [0, 1, 0, 0],
         [0, 0, 1, 0],
-        [16, 16, 0, 1]
-      ]
-    },
-    {
-      "id": 9,
-      "parent": 8,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [24, 24, 0, 1]
+        [40, 40, 0, 1]
       ]
     }
   ]

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/visibility/layer-visible-content-expected.txt

@@ -6,10 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV class='container'",
-      "bounds": [200, 200]
-    },
     {
       "name": "LayoutBlockFlow DIV class='composited box'",
       "bounds": [10, 10],

third_party/blink/web_tests/flag-specific/disable-layout-ng/fast/borders/overflow-hidden-border-radius-force-backing-store-expected.txt

@@ -6,11 +6,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "LayoutBlockFlow (positioned) DIV id='outer'",
-      "bounds": [300, 300],
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow DIV id='content'",
       "bounds": [285, 1000],

third_party/blink/web_tests/flag-specific/disable-layout-ng/virtual/prefer_compositing_to_lcd_text/compositing/overflow/reparented-scrollbars-non-sc-anc-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [1208, 821],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutBlockFlow DIV id='scroller'",
+      "bounds": [1200, 1000],
+      "transform": 1
+    },
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [1200, 10000],
+      "transform": 1
+    },
+    {
+      "name": "ContentsLayer for Vertical Scrollbar Layer",
+      "position": [1193, 0],
+      "bounds": [7, 1000],
+      "transform": 1
+    },
+    {
+      "name": "ContentsLayer for Horizontal Scrollbar Layer",
+      "position": [0, 593],
+      "bounds": [793, 7]
+    },
+    {
+      "name": "ContentsLayer for Vertical Scrollbar Layer",
+      "position": [793, 0],
+      "bounds": [7, 593]
+    },
+    {
+      "name": "Scroll Corner Layer",
+      "position": [793, 593],
+      "bounds": [7, 7]
+    }
+  ],
+  "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/virtual/prefer_compositing_to_lcd_text/compositing/overflow/rotate-clip-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutBlockFlow DIV",
+      "bounds": [400, 400],
+      "contentsOpaque": true,
+      "backgroundColor": "#0000FF",
+      "transform": 3
+    }
+  ],
+  "transforms": [
+    {
+      "id": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [108, 100, 0, 1]
+      ]
+    },
+    {
+      "id": 2,
+      "parent": 1,
+      "transform": [
+        [0.707106781186548, 0.707106781186548, 0, 0],
+        [-0.707106781186548, 0.707106781186548, 0, 0],
+        [0, 0, 1, 0],
+        [0, 0, 0, 1]
+      ],
+      "origin": [120, 120]
+    },
+    {
+      "id": 3,
+      "parent": 2,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [20, 20, 0, 1]
+      ]
+    }
+  ]
+}
+

third_party/blink/web_tests/flag-specific/disable-layout-ng/virtual/threaded/compositing/visibility/layer-visible-content-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutBlockFlow DIV class='composited box'",
+      "bounds": [10, 10],
+      "drawsContent": false
+    },
+    {
+      "name": "LayoutBlockFlow PRE id='layer-tree'",
+      "bounds": [800, 16]
+    }
+  ]
+}
+

third_party/blink/web_tests/virtual/prefer_compositing_to_lcd_text/compositing/overflow/rotate-clip-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutNGBlockFlow DIV",
+      "bounds": [400, 400],
+      "contentsOpaque": true,
+      "backgroundColor": "#0000FF",
+      "transform": 3
+    }
+  ],
+  "transforms": [
+    {
+      "id": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [108, 100, 0, 1]
+      ]
+    },
+    {
+      "id": 2,
+      "parent": 1,
+      "transform": [
+        [0.707106781186548, 0.707106781186548, 0, 0],
+        [-0.707106781186548, 0.707106781186548, 0, 0],
+        [0, 0, 1, 0],
+        [0, 0, 0, 1]
+      ],
+      "origin": [120, 120]
+    },
+    {
+      "id": 3,
+      "parent": 2,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [20, 20, 0, 1]
+      ]
+    }
+  ]
+}
+

third_party/blink/web_tests/virtual/threaded/compositing/visibility/layer-visible-content-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutNGBlockFlow DIV class='composited box'",
+      "bounds": [10, 10],
+      "drawsContent": false
+    },
+    {
+      "name": "LayoutNGBlockFlow PRE id='layer-tree'",
+      "bounds": [800, 16]
+    }
+  ]
+}
+