Remove is_root_for_isolated_group from cc::Layer

Now that BlinkGenPropertyTrees has launched, there is no need to track
is_root_for_isolated_group on cc::Layer as it is now tracked using
render surface reasons.

Bug: 993936
Change-Id: Ifa5b0b497392d8cb4020826139a6270c2faaf20e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815610
Commit-Queue: Philip Rogers <pdr@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#698552}

cc/layers/layer.cc

@@ -94,7 +94,6 @@ Layer::Inputs::Inputs(int layer_id)
       opacity(1.f),
       blend_mode(SkBlendMode::kSrcOver),
       masks_to_bounds(false),
-      is_root_for_isolated_group(false),
       hit_testable(false),
       contents_opaque(false),
       is_drawable(false),
@@ -781,15 +780,6 @@ void Layer::SetBlendMode(SkBlendMode blend_mode) {
   SetPropertyTreesNeedRebuild();
 }
 
-void Layer::SetIsRootForIsolatedGroup(bool root) {
-  DCHECK(IsPropertyChangeAllowed());
-  if (inputs_.is_root_for_isolated_group == root)
-    return;
-  inputs_.is_root_for_isolated_group = root;
-  SetPropertyTreesNeedRebuild();
-  SetNeedsCommit();
-}
-
 void Layer::SetHitTestable(bool should_hit_test) {
   DCHECK(IsPropertyChangeAllowed());
   if (inputs_.hit_testable == should_hit_test)

cc/layers/layer.h

@@ -258,15 +258,6 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
   void SetBlendMode(SkBlendMode blend_mode);
   SkBlendMode blend_mode() const { return inputs_.blend_mode; }
 
-  // A layer is root for an isolated group when it and all its descendants are
-  // drawn over a black and fully transparent background, creating an isolated
-  // group. It should be used along with SetBlendMode(), in order to restrict
-  // layers within the group to blend with layers outside this group.
-  void SetIsRootForIsolatedGroup(bool root);
-  bool is_root_for_isolated_group() const {
-    return inputs_.is_root_for_isolated_group;
-  }
-
   // Set or get the list of filter effects to be applied to the contents of the
   // layer and its subtree (together as a single composited entity) when
   // drawing them into their target.
@@ -861,8 +852,6 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
 
     bool masks_to_bounds : 1;
 
-    bool is_root_for_isolated_group : 1;
-
     // Hit testing depends on this bit.
     bool hit_testable : 1;
 

cc/layers/layer_unittest.cc

@@ -941,7 +941,6 @@ TEST_F(LayerTest, CheckPropertyChangeCausesCorrectBehavior) {
   EXPECT_SET_NEEDS_COMMIT(1, test_layer->SetIsFastRoundedCorner(true));
   EXPECT_SET_NEEDS_COMMIT(1, test_layer->SetOpacity(0.5f));
   EXPECT_SET_NEEDS_COMMIT(1, test_layer->SetBlendMode(SkBlendMode::kHue));
-  EXPECT_SET_NEEDS_COMMIT(1, test_layer->SetIsRootForIsolatedGroup(true));
   EXPECT_SET_NEEDS_COMMIT(1, test_layer->SetContentsOpaque(true));
   EXPECT_SET_NEEDS_COMMIT(1, test_layer->SetPosition(gfx::PointF(4.f, 9.f)));
   // We can use any layer pointer here since we aren't syncing for real.

cc/trees/effect_node.cc

@@ -122,8 +122,6 @@ const char* RenderSurfaceReasonToString(RenderSurfaceReason reason) {
       return "clip axis alignment";
     case RenderSurfaceReason::kMask:
       return "mask";
-    case RenderSurfaceReason::kRootOrIsolatedGroup:
-      return "root or isolated group";
     case RenderSurfaceReason::kTrilinearFiltering:
       return "trilinear filtering";
     case RenderSurfaceReason::kCache:

cc/trees/effect_node.h

@@ -37,7 +37,6 @@ enum class RenderSurfaceReason : uint8_t {
   kClipPath,
   kClipAxisAlignment,
   kMask,
-  kRootOrIsolatedGroup,
   kTrilinearFiltering,
   kCache,
   kCopyRequest,

cc/trees/layer_tree_host_pixeltest_blending.cc

@@ -223,7 +223,7 @@ class LayerTreeHostBlendingPixelTest
     scoped_refptr<Layer> background =
         CreateColorfulBackdropLayer(kRootWidth, kRootHeight);
 
-    background->SetIsRootForIsolatedGroup(true);
+    background->SetForceRenderSurfaceForTesting(true);
     root->AddChild(background);
 
     CreateBlendingColorLayers(kRootWidth, kRootHeight, background.get(), flags);
@@ -351,7 +351,7 @@ TEST_P(LayerTreeHostBlendingPixelTest, BlendingWithTransparent) {
       CreateSolidColorLayer(gfx::Rect(kRootWidth, kRootHeight), kCSSOrange);
 
   root->AddChild(background);
-  background->SetIsRootForIsolatedGroup(true);
+  background->SetForceRenderSurfaceForTesting(true);
 
   // Orange child layers will blend with the green background
   gfx::Rect child_rect(kRootWidth, kRootHeight);

cc/trees/layer_tree_host_pixeltest_masks.cc

@@ -833,7 +833,6 @@ TEST_P(LayerTreeHostMaskAsBlendingPixelTest, PixelAlignedNoop) {
   mask_isolation->SetPosition(gfx::PointF(20, 20));
   mask_isolation->SetBounds(gfx::Size(350, 250));
   mask_isolation->SetMasksToBounds(true);
-  mask_isolation->SetIsRootForIsolatedGroup(true);
   root->AddChild(mask_isolation);
 
   scoped_refptr<Layer> content =
@@ -858,7 +857,7 @@ TEST_P(LayerTreeHostMaskAsBlendingPixelTest, PixelAlignedClippedCircle) {
   mask_isolation->SetPosition(gfx::PointF(20, 20));
   mask_isolation->SetBounds(gfx::Size(350, 250));
   mask_isolation->SetMasksToBounds(true);
-  mask_isolation->SetIsRootForIsolatedGroup(true);
+  mask_isolation->SetForceRenderSurfaceForTesting(true);
   root->AddChild(mask_isolation);
 
   scoped_refptr<Layer> content =
@@ -895,7 +894,7 @@ TEST_P(LayerTreeHostMaskAsBlendingPixelTest,
   mask_isolation->SetPosition(gfx::PointF(20, 20));
   mask_isolation->SetBounds(gfx::Size(350, 250));
   mask_isolation->SetMasksToBounds(true);
-  mask_isolation->SetIsRootForIsolatedGroup(true);
+  mask_isolation->SetForceRenderSurfaceForTesting(true);
   root->AddChild(mask_isolation);
 
   scoped_refptr<Layer> content =
@@ -936,7 +935,6 @@ TEST_P(LayerTreeHostMaskAsBlendingPixelTest, RotatedClippedCircle) {
   }
   mask_isolation->SetBounds(gfx::Size(350, 250));
   mask_isolation->SetMasksToBounds(true);
-  mask_isolation->SetIsRootForIsolatedGroup(true);
   root->AddChild(mask_isolation);
 
   scoped_refptr<Layer> content =
@@ -983,7 +981,6 @@ TEST_P(LayerTreeHostMaskAsBlendingPixelTest, RotatedClippedCircleUnderflow) {
   }
   mask_isolation->SetBounds(gfx::Size(350, 250));
   mask_isolation->SetMasksToBounds(true);
-  mask_isolation->SetIsRootForIsolatedGroup(true);
   root->AddChild(mask_isolation);
 
   scoped_refptr<Layer> content =

cc/trees/property_tree_builder.cc

@@ -418,14 +418,6 @@ RenderSurfaceReason ComputeRenderSurfaceReason(const MutatorHost& mutator_host,
     DCHECK(!is_root);
     return RenderSurfaceReason::kOpacity;
   }
-  // If the layer has isolation.
-  // TODO(rosca): to be optimized - create separate rendering surface only when
-  // the blending descendants might have access to the content behind this layer
-  // (layer has transparent background or descendants overflow).
-  // https://code.google.com/p/chromium/issues/detail?id=301738
-  if (layer->is_root_for_isolated_group()) {
-    return RenderSurfaceReason::kRootOrIsolatedGroup;
-  }
 
   // If we force it.
   if (layer->force_render_surface_for_testing())

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

@@ -249,7 +249,6 @@ void CompositedLayerMapping::CreatePrimaryGraphicsLayer() {
   UpdateOpacity(GetLayoutObject().StyleRef());
   UpdateTransform(GetLayoutObject().StyleRef());
   UpdateLayerBlendMode(GetLayoutObject().StyleRef());
-  UpdateIsRootForIsolatedGroup();
 }
 
 void CompositedLayerMapping::DestroyGraphicsLayers() {
@@ -289,16 +288,6 @@ void CompositedLayerMapping::UpdateLayerBlendMode(const ComputedStyle& style) {
   SetBlendMode(style.GetBlendMode());
 }
 
-void CompositedLayerMapping::UpdateIsRootForIsolatedGroup() {
-  bool isolate = owning_layer_.ShouldIsolateCompositedDescendants();
-
-  // non stacking context layers should never isolate
-  DCHECK(owning_layer_.GetLayoutObject().StyleRef().IsStackingContext() ||
-         !isolate);
-
-  graphics_layer_->SetIsRootForIsolatedGroup(isolate);
-}
-
 void CompositedLayerMapping::UpdateBackgroundPaintsOntoScrollingContentsLayer(
     bool& invalidate_graphics_layer,
     bool& invalidate_scrolling_contents_layer) {
@@ -898,7 +887,6 @@ void CompositedLayerMapping::UpdateGraphicsLayerGeometry(
     owning_layer_.GetScrollableArea()->PositionOverflowControls();
 
   UpdateLayerBlendMode(GetLayoutObject().StyleRef());
-  UpdateIsRootForIsolatedGroup();
   UpdateContentsRect();
   UpdateBackgroundColor();
 

third_party/blink/renderer/core/paint/compositing/composited_layer_mapping.h

@@ -394,7 +394,6 @@ class CORE_EXPORT CompositedLayerMapping final : public GraphicsLayerClient {
   void UpdateOpacity(const ComputedStyle&);
   void UpdateTransform(const ComputedStyle&);
   void UpdateLayerBlendMode(const ComputedStyle&);
-  void UpdateIsRootForIsolatedGroup();
   // Return the opacity value that this layer should use for compositing.
   float CompositingOpacity(float layout_object_opacity) const;
 

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

@@ -101,9 +101,6 @@ std::unique_ptr<JSONObject> GraphicsLayerAsJSON(
                                                        layer->GetBlendMode()));
   }
 
-  if (layer->IsRootForIsolatedGroup())
-    json->SetBoolean("isolate", true);
-
   if (layer->ContentsOpaque())
     json->SetBoolean("contentsOpaque", true);
 

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

@@ -701,14 +701,6 @@ BlendMode GraphicsLayer::GetBlendMode() const {
   return BlendModeFromSkBlendMode(CcLayer()->blend_mode());
 }
 
-bool GraphicsLayer::IsRootForIsolatedGroup() const {
-  return CcLayer()->is_root_for_isolated_group();
-}
-
-void GraphicsLayer::SetIsRootForIsolatedGroup(bool isolated) {
-  CcLayer()->SetIsRootForIsolatedGroup(isolated);
-}
-
 void GraphicsLayer::SetHitTestable(bool should_hit_test) {
   if (hit_testable_ == should_hit_test)
     return;

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

@@ -174,8 +174,6 @@ class PLATFORM_EXPORT GraphicsLayer : public cc::LayerClient,
 
   BlendMode GetBlendMode() const;
   void SetBlendMode(BlendMode);
-  bool IsRootForIsolatedGroup() const;
-  void SetIsRootForIsolatedGroup(bool);
 
   void SetHitTestable(bool);
   bool GetHitTestable() const { return hit_testable_; }

third_party/blink/web_tests/css3/blending/mix-blend-mode-composited-reason-children-expected.txt

@@ -33,7 +33,6 @@
       "name": "LayoutBlockFlow (positioned) DIV class='stacking-context'",
       "position": [8, 8],
       "bounds": [160, 90],
-      "isolate": true,
       "contentsOpaque": true,
       "backgroundColor": "#008000"
     },

third_party/blink/web_tests/css3/blending/mix-blend-mode-isolation-2-stacking-contexts-expected.txt

@@ -33,7 +33,6 @@
       "name": "LayoutBlockFlow (positioned) DIV class='stacking-context'",
       "position": [8, 8],
       "bounds": [160, 90],
-      "isolate": true,
       "contentsOpaque": true,
       "backgroundColor": "#008000"
     },
@@ -59,7 +58,6 @@
     {
       "name": "LayoutBlockFlow (positioned) DIV class='stacking-context'",
       "bounds": [160, 90],
-      "isolate": true,
       "contentsOpaque": true,
       "backgroundColor": "#008000",
       "transform": 2

third_party/blink/web_tests/css3/blending/mix-blend-mode-isolation-layer-expected.txt

@@ -26,7 +26,6 @@
       "name": "LayoutBlockFlow (positioned) DIV class='stacking-context'",
       "position": [8, 8],
       "bounds": [160, 90],
-      "isolate": true,
       "contentsOpaque": true,
       "backgroundColor": "#008000"
     },

third_party/blink/web_tests/css3/blending/mix-blend-mode-isolation-remove-expected.txt

@@ -20,7 +20,6 @@
     {
       "name": "LayoutBlockFlow DIV class='accelerated-stacking-context'",
       "bounds": [784, 90],
-      "isolate": true,
       "contentsOpaque": true,
       "backgroundColor": "#0000FF",
       "transform": 1

third_party/blink/web_tests/platform/mac/css3/blending/mix-blend-mode-composited-layers-expected.txt

@@ -20,8 +20,7 @@
     },
     {
       "name": "LayoutBlockFlow HTML",
-      "bounds": [800, 69],
-      "isolate": true
+      "bounds": [800, 69]
     },
     {
       "name": "LayoutBlockFlow DIV",

third_party/blink/web_tests/platform/win/css3/blending/mix-blend-mode-composited-layers-expected.txt

@@ -20,8 +20,7 @@
     },
     {
       "name": "LayoutBlockFlow HTML",
-      "bounds": [800, 70],
-      "isolate": true
+      "bounds": [800, 70]
     },
     {
       "name": "LayoutBlockFlow DIV",