Removing the kInlineTransform compositing reason

This optimization was the cause of at least one bug (crbug.com/812166), and
will hopefully not be needed once Composite After Paint is implemented.

Bug: 812166
Change-Id: I2024b887949904bad5515d76b2fa29607dae3ff9
Reviewed-on: https://chromium-review.googlesource.com/c/1354572
Commit-Queue: Mason Freed <masonfreed@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612670}

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

@@ -94,9 +94,6 @@ CompositingReasonFinder::PotentialCompositingReasonsFromStyle(
       !style.SubtreeWillChangeContents())
     reasons |= CompositingReason::kWillChangeCompositingHint;
 
-  if (style.HasInlineTransform())
-    reasons |= CompositingReason::kInlineTransform;
-
   if (style.UsedTransformStyle3D() == ETransformStyle3D::kPreserve3d)
     reasons |= CompositingReason::kPreserve3DWith3DDescendants;
 

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

@@ -608,11 +608,6 @@ void CompositingRequirementsUpdater::UpdateRecursive(
       will_be_composited_or_squashed = true;
     }
 
-    if (will_be_composited_or_squashed) {
-      reasons_to_composite |= layer->PotentialCompositingReasonsFromStyle() &
-                              CompositingReason::kInlineTransform;
-    }
-
     if (will_be_composited_or_squashed &&
         layer->GetLayoutObject().StyleRef().HasBlendMode()) {
       current_recursion_data.has_unisolated_composited_blending_descendant_ =
@@ -631,12 +626,9 @@ void CompositingRequirementsUpdater::UpdateRecursive(
     bool is_composited_clipping_layer =
         can_be_composited && (reasons_to_composite &
                               CompositingReason::kClipsCompositingDescendants);
-    bool is_composited_with_inline_transform =
-        reasons_to_composite & CompositingReason::kInlineTransform;
     if ((!child_recursion_data.testing_overlap_ &&
          !is_composited_clipping_layer) ||
-        layer->GetLayoutObject().StyleRef().HasCurrentTransformAnimation() ||
-        is_composited_with_inline_transform)
+        layer->GetLayoutObject().StyleRef().HasCurrentTransformAnimation())
       current_recursion_data.testing_overlap_ = false;
 
     if (child_recursion_data.compositing_ancestor_ == layer)

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

@@ -76,33 +76,6 @@ TEST_F(CompositingRequirementsUpdaterTest,
   EXPECT_EQ(CompositingReason::kOverlap, target->GetCompositingReasons());
 }
 
-TEST_F(CompositingRequirementsUpdaterTest,
-       NoAssumedOverlapReasonForNonSelfPaintingLayer) {
-  SetBodyInnerHTML(R"HTML(
-    <style>
-      #target {
-       overflow: auto;
-       width: 100px;
-       height: 100px;
-     }
-    </style>
-    <div style="position: relative; width: 500px; height: 300px;
-        transform: translateZ(0)"></div>
-    <div id=target></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::kAssumedOverlap,
-            target->GetCompositingReasons());
-}
-
 TEST_F(CompositingRequirementsUpdaterTest,
        NoDescendantReasonForNonSelfPaintingLayer) {
   SetBodyInnerHTML(R"HTML(

third_party/blink/renderer/core/paint/paint_layer.cc

@@ -3064,15 +3064,8 @@ bool PaintLayer::AttemptDirectCompositingUpdate(
   if (!rare_data_ || !rare_data_->composited_layer_mapping)
     return false;
 
-  // To cut off almost all the work in the compositing update for
-  // this case, we treat inline transforms has having assumed overlap
-  // (similar to how we treat animated transforms). Notice that we read
-  // CompositingReasonInlineTransform from the m_compositingReasons, which
-  // means that the inline transform actually triggered assumed overlap in
-  // the overlap map.
-  if (diff.TransformChanged() &&
-      (!rare_data_ || !(rare_data_->compositing_reasons &
-                        CompositingReason::kInlineTransform)))
+  // If a transform changed, we can't use the fast path.
+  if (diff.TransformChanged())
     return false;
 
   // We composite transparent Layers differently from non-transparent

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

@@ -156,9 +156,6 @@ constexpr CompositingReasonStringMap kCompositingReasonsStringMap[] = {
      "with no scrolling contents"},
     {CompositingReason::kLayerForDecoration, "layerForDecoration",
      "Layer painted on top of other layers as decoration"},
-    {CompositingReason::kInlineTransform, "inlineTransform",
-     "Has an inline transform, which causes subsequent layers to assume "
-     "overlap"},
 
 };
 

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

@@ -82,11 +82,7 @@ using CompositingReasons = uint64_t;
   V(LayerForAncestorClippingMask)                                             \
   V(LayerForScrollingBlockSelection)                                          \
   /* Composited layer painted on top of all other layers as decoration. */    \
-  V(LayerForDecoration)                                                       \
-                                                                              \
-  /* Composited elements with inline transforms trigger assumed overlap so    \
-  that we can update their transforms quickly. */                             \
-  V(InlineTransform)
+  V(LayerForDecoration)
 
 class PLATFORM_EXPORT CompositingReason {
  private:
@@ -147,7 +143,7 @@ class PLATFORM_EXPORT CompositingReason {
 
     kComboAllStyleDeterminedReasons = kComboAllDirectStyleDeterminedReasons |
                                       kComboCompositedDescendants |
-                                      kCombo3DDescendants | kInlineTransform,
+                                      kCombo3DDescendants,
 
     kComboSquashableReasons =
         kOverlap | kAssumedOverlap | kOverflowScrollingParent,

third_party/blink/web_tests/SmokeTests

@@ -26,7 +26,6 @@ compositing/geometry/limit-layer-bounds-positioned-transition.html
 compositing/gestures/gesture-tapHighlight-no-graphics-layer-region-based-multicol.html
 compositing/iframes/visibility-hidden-transformed-content.html
 compositing/images/clip-on-directly-composited-image.html
-compositing/layer-creation/assumed-overlap-for-inline-transform.html
 compositing/layer-creation/fixed-position-out-of-view-dynamic.html
 compositing/layer-creation/fixed-position-out-of-view.html
 compositing/reflections/empty-reflection-with-mask.html

third_party/blink/web_tests/compositing/gestures/gesture-tapHighlight-1-overflow-div-scrolled-late-composite-expected.html

@@ -8,12 +8,12 @@
 <div style="transform: translateZ(0); position: relative; left: 10px; top: 10px"></div>
 <div id="targetDiv" style="position: relative; left: 10px; top: 40px; width: 200px; height: 100px; overflow-y: scroll; overflow-x: scroll;">
 <div id="divToForceCompositedLayer">
-<a href="">Link 1</a><br>
-<a href="">Link 2</a><br>
-<a href="">Link 3</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 <a href="" class="activeLink" id="targetLink">Target Link.</a><br>
-<a href="">Link 4</a><br>
-<a href="">Link 5</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 </div></div>
 <div style="position: relative; left: 10px; top: 80px">
 This test is successful if "Target Link" above is covered in a green rectangle with square corners.

third_party/blink/web_tests/compositing/gestures/gesture-tapHighlight-1-overflow-div-scrolled-late-composite.html

@@ -8,12 +8,12 @@
 <div style="transform: translateZ(0); position: relative; left: 10px; top: 10px"></div>
 <div id="targetDiv" style="position: relative; left: 10px; top: 40px; width: 200px; height: 100px; overflow-y: scroll; overflow-x: scroll;">
 <div id="divToForceCompositedLayer">
-<a href="">Link 1</a><br>
-<a href="">Link 2</a><br>
-<a href="">Link 3</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 <a class="opaqueHighlight" href="" id="targetLink">Target Link.</a><br>
-<a href="">Link 4</a><br>
-<a href="">Link 5</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 </div></div>
 <div style="position: relative; left: 10px; top: 80px">
 This test is successful if "Target Link" above is covered in a green rectangle with square corners.

third_party/blink/web_tests/compositing/gestures/gesture-tapHighlight-1-overflow-div-scrolled-late-noncomposite-expected.html

@@ -7,12 +7,12 @@
 <div style="transform: translateZ(0); position: relative; left: 10px; top: 10px"></div>
 <div id="targetDiv" style="position: relative; left: 10px; top: 40px; width: 200px; height: 100px; overflow-y: scroll; overflow-x: scroll;">
 <div id="divToControlCompositedLayer" style="transform: translateZ(0);">
-<a href="">Link 1</a><br>
-<a href="">Link 2</a><br>
-<a href="">Link 3</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 <span class="fauxHighlight" id="targetLink">Target Link.</span><br>
-<a href="">Link 4</a><br>
-<a href="">Link 5</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 </div></div>
 <div style="position: relative; left: 10px; top: 80px">
 This test is successful if "Target Link" above is covered in a green rectangle with square corners.

third_party/blink/web_tests/compositing/gestures/gesture-tapHighlight-1-overflow-div-scrolled-late-noncomposite.html

@@ -9,12 +9,12 @@
 <div style="transform: translateZ(0); position: relative; left: 10px; top: 10px"></div>
 <div id="targetDiv" style="position: relative; left: 10px; top: 40px; width: 200px; height: 100px; overflow-y: scroll; overflow-x: scroll;">
 <div id="divToControlCompositedLayer" style="transform: translateZ(0);">
-<a href="">Link 1</a><br>
-<a href="">Link 2</a><br>
-<a href="">Link 3</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 <a class="opaqueHighlight needsFix" href="" id="targetLink">Target Link.</a><br>
-<a href="">Link 4</a><br>
-<a href="">Link 5</a><br>
+<a href="">AAAAAA</a><br>
+<a href="">AAAAAA</a><br>
 </div></div>
 <div style="position: relative; left: 10px; top: 80px">
 This test is successful if "Target Link" above is covered in a green rectangle with square corners.

third_party/blink/web_tests/compositing/gestures/gesture-tapHighlight-on-promoted-overflow-div-scrolled-expected.html

@@ -15,12 +15,12 @@
   <body onload="runTest();">
     <div style="transform: translateZ(0); position: relative; left: 10px; top: 10px"></div>
     <div id="targetDiv" style="position: relative; left: 10px; top: 40px; width: 200px; height: 100px; overflow-y: scroll; overflow-x: scroll;">
-      <a href="">Link 1</a><br>
-      <a href="">Link 2</a><br>
-      <a href="">Link 3</a><br>
+      <a href="">AAAAAA</a><br>
+      <a href="">AAAAAA</a><br>
+      <a href="">AAAAAA</a><br>
       <a href="" class="activeLink" id="targetLink">Target Link.</a><br>
-      <a href="">Link 4</a><br>
-      <a href="">Link 5</a><br>
+      <a href="">AAAAAA</a><br>
+      <a href="">AAAAAA</a><br>
     </div>
     <div style="position: relative; left: 10px; top: 80px">
       This test is successful if "Target Link" above is covered in a green

third_party/blink/web_tests/compositing/gestures/gesture-tapHighlight-on-promoted-overflow-div-scrolled.html

@@ -36,12 +36,12 @@
   <body onload="runTest();">
     <div style="transform: translateZ(0); position: relative; left: 10px; top: 10px"></div>
     <div id="targetDiv" style="position: relative; left: 10px; top: 40px; width: 200px; height: 100px; overflow-y: scroll; overflow-x: scroll;">
-      <a href="">Link 1</a><br>
-      <a href="">Link 2</a><br>
-      <a href="">Link 3</a><br>
+      <a href="">AAAAAA</a><br>
+      <a href="">AAAAAA</a><br>
+      <a href="">AAAAAA</a><br>
       <a class="opaqueHighlight" href="" id="targetLink">Target Link.</a><br>
-      <a href="">Link 4</a><br>
-      <a href="">Link 5</a><br>
+      <a href="">AAAAAA</a><br>
+      <a href="">AAAAAA</a><br>
     </div>
     <div style="position: relative; left: 10px; top: 80px">
       This test is successful if "Target Link" above is covered in a green

third_party/blink/web_tests/compositing/layer-creation/assumed-overlap-for-inline-transform.html

-<!DOCTYPE html>
-<style>
-.box {
-  position: relative;
-  width: 100px;
-  height: 100px;
-}
-</style>
-<div class="box" style="transform: translateZ(0); background-color: blue;"></div>
-<div class="box" style="background-color: yellow;"></div>
-<script>
-if (window.testRunner) {
-    testRunner.dumpAsText();
-    testRunner.setCustomTextOutput(internals.layerTreeAsText(document));
-}
-</script>

third_party/blink/web_tests/compositing/overflow/avoid-ancestor-clip-for-scroll-children.html

@@ -31,7 +31,7 @@
     <div class="translated">
       <div class="scrolled"></div>
     </div>
-    <div class="translated" style="transform: translate(0,430px)">
+    <div class="translated" style="transform: translate3D(0px,430px,0px)">
       <div class="scrolled"></div>
     </div>
   </div>

third_party/blink/web_tests/compositing/squashing/frame-clip-squashed-scrolled-expected.txt

@@ -18,22 +18,11 @@
       "backgroundColor": "#FFFFFF",
       "transform": 1
     },
-    {
-      "name": "Squashing Containment Layer",
-      "drawsContent": false,
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow DIV",
       "contentsOpaque": true,
       "drawsContent": false,
       "transform": 2
-    },
-    {
-      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (relative positioned) DIV)",
-      "position": [8, 8],
-      "bounds": [102, 2002],
-      "transform": 1
     }
   ],
   "transforms": [
@@ -55,8 +44,7 @@
         [0, 1, 0, 0],
         [0, 0, 1, 0],
         [8, 8, 0, 1]
-      ],
-      "flattenInheritedTransform": false
+      ]
     }
   ]
 }

third_party/blink/web_tests/compositing/squashing/squash-onto-distant-relative-expected.txt

@@ -17,21 +17,12 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
-    {
-      "name": "Squashing Containment Layer",
-      "drawsContent": false
-    },
     {
       "name": "LayoutBlockFlow (positioned) DIV id='squashing'",
       "bounds": [1, 1],
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF",
       "transform": 1
-    },
-    {
-      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV id='squashed')",
-      "position": [600, 0],
-      "bounds": [200, 200]
     }
   ],
   "transforms": [
@@ -42,8 +33,7 @@
         [0, 1, 0, 0],
         [0, 0, 1, 0],
         [-33554430, 0, 0, 1]
-      ],
-      "flattenInheritedTransform": false
+      ]
     }
   ]
 }

third_party/blink/web_tests/compositing/squashing/squashing-inside-perspective-expected.txt

@@ -28,21 +28,12 @@
       "drawsContent": false,
       "transform": 2
     },
-    {
-      "name": "Squashing Containment Layer",
-      "drawsContent": false,
-      "transform": 2
-    },
     {
       "name": "LayoutBlockFlow (positioned) DIV",
       "bounds": [200, 200],
       "contentsOpaque": true,
       "backgroundColor": "#00008B",
       "transform": 3
-    },
-    {
-      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV)",
-      "transform": 2
     }
   ],
   "transforms": [

third_party/blink/web_tests/paint/invalidation/compositing/repaint-via-layout-offset-expected.txt

@@ -29,7 +29,7 @@
       "transform": 1
     },
     {
-      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV id='container')",
+      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) SPAN class='child')",
       "position": [50, 50],
       "bounds": [50, 50],
       "paintInvalidations": [

third_party/blink/web_tests/paint/invalidation/scroll/overflow-scroll-composited-non-stacking-child-expected.txt

@@ -40,23 +40,6 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFDDBB",
       "transform": 1
-    },
-    {
-      "name": "Ancestor Clipping Layer",
-      "position": [23, 65],
-      "bounds": [285, 175],
-      "drawsContent": false
-    },
-    {
-      "name": "LayoutBlockFlow (relative positioned) DIV class='list'",
-      "position": [43, 35],
-      "bounds": [180, 250],
-      "drawsContent": false
-    },
-    {
-      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (relative positioned) DIV class='commit')",
-      "position": [43, 35],
-      "bounds": [180, 250]
     }
   ],
   "transforms": [

third_party/blink/web_tests/paint/invalidation/svg/transform-focus-ring-repaint-expected.txt

@@ -17,6 +17,10 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
+    {
+      "name": "Squashing Containment Layer",
+      "drawsContent": false
+    },
     {
       "name": "LayoutBlockFlow (positioned) DIV id='target'",
       "position": [7, 57],
@@ -37,32 +41,9 @@
       ]
     },
     {
-      "name": "LayoutBlockFlow (positioned) DIV",
-      "bounds": [440, 300],
-      "backgroundColor": "#0000FF",
-      "transform": 2
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [108, 158, 0, 1]
-      ]
-    },
-    {
-      "id": 2,
-      "parent": 1,
-      "transform": [
-        [0, 1, 0, 0],
-        [-1, 0, 0, 0],
-        [0, 0, 1, 0],
-        [0, 0, 0, 1]
-      ],
-      "origin": [150, 150]
+      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV)",
+      "position": [108, 158],
+      "bounds": [300, 440]
     }
   ]
 }

third_party/blink/web_tests/platform/mac/compositing/squashing/frame-clip-squashed-scrolled-expected.txt

@@ -18,22 +18,11 @@
       "backgroundColor": "#FFFFFF",
       "transform": 1
     },
-    {
-      "name": "Squashing Containment Layer",
-      "drawsContent": false,
-      "transform": 1
-    },
     {
       "name": "LayoutBlockFlow DIV",
       "contentsOpaque": true,
       "drawsContent": false,
       "transform": 2
-    },
-    {
-      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (relative positioned) DIV)",
-      "position": [8, 8],
-      "bounds": [102, 2002],
-      "transform": 1
     }
   ],
   "transforms": [
@@ -55,8 +44,7 @@
         [0, 1, 0, 0],
         [0, 0, 1, 0],
         [8, 8, 0, 1]
-      ],
-      "flattenInheritedTransform": false
+      ]
     }
   ]
 }

third_party/blink/web_tests/platform/mac/paint/invalidation/svg/transform-focus-ring-repaint-expected.txt

@@ -17,6 +17,10 @@
       "contentsOpaque": true,
       "backgroundColor": "#FFFFFF"
     },
+    {
+      "name": "Squashing Containment Layer",
+      "drawsContent": false
+    },
     {
       "name": "LayoutBlockFlow (positioned) DIV id='target'",
       "position": [5, 55],
@@ -37,32 +41,9 @@
       ]
     },
     {
-      "name": "LayoutBlockFlow (positioned) DIV",
-      "bounds": [440, 300],
-      "backgroundColor": "#0000FF",
-      "transform": 2
-    }
-  ],
-  "transforms": [
-    {
-      "id": 1,
-      "transform": [
-        [1, 0, 0, 0],
-        [0, 1, 0, 0],
-        [0, 0, 1, 0],
-        [108, 158, 0, 1]
-      ]
-    },
-    {
-      "id": 2,
-      "parent": 1,
-      "transform": [
-        [0, 1, 0, 0],
-        [-1, 0, 0, 0],
-        [0, 0, 1, 0],
-        [0, 0, 0, 1]
-      ],
-      "origin": [150, 150]
+      "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV)",
+      "position": [108, 158],
+      "bounds": [300, 440]
     }
   ]
 }