Force use of and cache render surface.

cc/trees/damage_tracker_unittest.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/damage_tracker.h"
 
 #include <stddef.h>
 
 #include "cc/base/filter_operation.h"
 #include "cc/base/filter_operations.h"
@@ skipping 171 matching lines @@
 
   EXPECT_EQ(2, GetRenderSurface(root)->num_contributors());
   EXPECT_TRUE(root->contributes_to_drawn_render_surface());
   EXPECT_TRUE(child->contributes_to_drawn_render_surface());
 
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
 
   EXPECT_EQ(gfx::Rect(500, 500).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, SanityCheckTestTreeWithTwoSurfaces) {
   // Sanity check that the complex test tree will actually produce the expected
   // render surfaces.
 
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
 
   LayerImpl* child1 = root->test_properties()->children[0];
   LayerImpl* child2 = root->test_properties()->children[1];
 
   gfx::Rect child_damage_rect;
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
 
   EXPECT_NE(GetRenderSurface(child1), GetRenderSurface(root));
   EXPECT_EQ(GetRenderSurface(child2), GetRenderSurface(root));
   EXPECT_EQ(3, GetRenderSurface(root)->num_contributors());
   EXPECT_EQ(2, GetRenderSurface(child1)->num_contributors());
 
   // The render surface for child1 only has a content_rect that encloses
   // grand_child1 and grand_child2, because child1 does not draw content.
   EXPECT_EQ(gfx::Rect(190, 190, 16, 18).ToString(),
             child_damage_rect.ToString());
   EXPECT_EQ(gfx::Rect(500, 500).ToString(), root_damage_rect.ToString());
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForUpdateRects) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   // CASE 1: Setting the update rect should cause the corresponding damage to
   //         the surface.
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(10, 11, 12, 13));
@@ skipping 24 matching lines @@
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(20, 25, 1, 2));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Damage position on the surface should be: position of update_rect (20, 25)
   // relative to the child (100, 100).
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(120, 125, 1, 2).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForLayerDamageRects) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   // CASE 1: Adding the layer damage rect should cause the corresponding damage
   // to the surface.
   ClearDamageForAllSurfaces(root);
   child->AddDamageRect(gfx::Rect(10, 11, 12, 13));
@@ skipping 37 matching lines @@
   child->AddDamageRect(gfx::Rect(10, 15, 3, 4));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Damage position on the surface should be: position of layer damage_rect
   // (20, 25) relative to the child (100, 100).
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(true, root_damage_rect.Contains(gfx::Rect(120, 125, 1, 2)));
   EXPECT_EQ(true, root_damage_rect.Contains(gfx::Rect(110, 115, 3, 4)));
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForLayerUpdateAndDamageRects) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   // CASE 1: Adding the layer damage rect and update rect should cause the
   // corresponding damage to the surface.
   ClearDamageForAllSurfaces(root);
   child->AddDamageRect(gfx::Rect(5, 6, 12, 13));
@@ skipping 26 matching lines @@
   child->AddDamageRect(gfx::Rect(20, 25, 2, 3));
   child->SetUpdateRect(gfx::Rect(5, 10, 7, 8));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Damage position on the surface should be: position of unified layer damage
   // rect and update rect (5, 10) relative to the child (100, 100).
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(true, root_damage_rect.Contains(gfx::Rect(105, 110, 17, 18)));
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForPropertyChanges) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   // CASE 1: The layer's property changed flag takes priority over update rect.
   //
   child->test_properties()->force_render_surface = true;
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(10, 11, 12, 13));
   root->layer_tree_impl()->SetOpacityMutated(child->element_id(), 0.5f);
   EmulateDrawingOneFrame(root);
 
   ASSERT_EQ(2, GetRenderSurface(root)->num_contributors());
 
   // Damage should be the entire child layer in target_surface space.
   gfx::Rect expected_rect = gfx::Rect(100, 100, 30, 30);
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(expected_rect.ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 
   // CASE 2: If a layer moves due to property change, it damages both the new
   //         location and the old (exposed) location. The old location is the
   //         entire old layer, not just the update_rect.
 
   // Cycle one frame of no change, just to sanity check that the next rect is
   // not because of the old damage state.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(root_damage_rect.IsEmpty());
 
   // Then, test the actual layer movement.
   ClearDamageForAllSurfaces(root);
   gfx::Transform translation;
   translation.Translate(100.f, 130.f);
   root->layer_tree_impl()->SetTransformMutated(child->element_id(),
                                                translation);
   EmulateDrawingOneFrame(root);
 
   // Expect damage to be the combination of the previous one and the new one.
   expected_rect.Union(gfx::Rect(200, 230, 30, 30));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_FLOAT_RECT_EQ(expected_rect, root_damage_rect);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  // Transform from browser animation should not be considered as damage from
+  // contributing layer since it is applied to the whole layer which has a
+  // render surface.
+  EXPECT_FALSE(GetRenderSurface(child)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+}
+
+TEST_F(DamageTrackerTest,
+       VerifyDamageForPropertyChangesFromContributingContents) {
+  LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
+  LayerImpl* child1 = root->test_properties()->children[0];
+  LayerImpl* child2 = root->test_properties()->children[1];
+  LayerImpl* grandchild1 = child1->test_properties()->children[0];
+
+  // CASE 1: The child1's opacity changed.
+  ClearDamageForAllSurfaces(root);
+  root->layer_tree_impl()->SetOpacityMutated(child1->element_id(), 0.5f);
+  EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child1)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+
+  // CASE 2: The layer2's opacity changed.
+  child2->test_properties()->force_render_surface = true;
+  root->layer_tree_impl()->property_trees()->needs_rebuild = true;
+  EmulateDrawingOneFrame(root);
+  ClearDamageForAllSurfaces(root);
+  root->layer_tree_impl()->SetOpacityMutated(child2->element_id(), 0.5f);
+  EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child1)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+
+  // CASE 3: The grandchild1's opacity changed.
+  grandchild1->test_properties()->force_render_surface = true;
+  root->layer_tree_impl()->property_trees()->needs_rebuild = true;
+  EmulateDrawingOneFrame(root);
+  ClearDamageForAllSurfaces(root);
+  root->layer_tree_impl()->SetOpacityMutated(grandchild1->element_id(), 0.5f);
+  EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+}
+
+TEST_F(DamageTrackerTest,
+       VerifyDamageForUpdateAndDamageRectsFromContributingContents) {
+  LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
+  LayerImpl* child1 = root->test_properties()->children[0];
+  LayerImpl* child2 = root->test_properties()->children[1];
+  LayerImpl* grandchild1 = child1->test_properties()->children[0];
+
+  // CASE 1: Adding the layer1's damage rect and update rect should cause the
+  // corresponding damage to the surface.
+  child1->SetDrawsContent(true);
+  ClearDamageForAllSurfaces(root);
+  child1->AddDamageRect(gfx::Rect(105, 106, 12, 15));
+  child1->SetUpdateRect(gfx::Rect(115, 116, 12, 15));
+  root->layer_tree_impl()->property_trees()->needs_rebuild = true;
+  EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+
+  // CASE 2: Adding the layer2's damage rect and update rect should cause the
+  // corresponding damage to the surface.
+  ClearDamageForAllSurfaces(root);
+  child2->AddDamageRect(gfx::Rect(11, 11, 12, 15));
+  child2->SetUpdateRect(gfx::Rect(12, 12, 12, 15));
+  EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child1)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+
+  // CASE 3: Adding the grandchild1's damage rect and update rect should cause
+  // the corresponding damage to the surface.
+  ClearDamageForAllSurfaces(root);
+  grandchild1->AddDamageRect(gfx::Rect(1, 0, 2, 5));
+  grandchild1->SetUpdateRect(gfx::Rect(2, 1, 2, 5));
+  EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageWhenSurfaceRemoved) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* surface = root->test_properties()->children[0];
   LayerImpl* child = surface->test_properties()->children[0];
   child->SetDrawsContent(true);
   EmulateDrawingOneFrame(root);
   ClearDamageForAllSurfaces(root);
 
   surface->test_properties()->force_render_surface = false;
   child->SetDrawsContent(false);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(290, 290, 16, 18).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForTransformedLayer) {
   // If a layer is transformed, the damage rect should still enclose the entire
   // transformed layer.
 
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
   child->test_properties()->force_render_surface = true;
 
   gfx::Transform rotation;
   rotation.Rotate(45.0);
 
   ClearDamageForAllSurfaces(root);
   child->test_properties()->transform_origin = gfx::Point3F(
       child->bounds().width() * 0.5f, child->bounds().height() * 0.5f, 0.f);
   child->SetPosition(gfx::PointF(85.f, 85.f));
   child->NoteLayerPropertyChanged();
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Sanity check that the layer actually moved to (85, 85), damaging its old
   // location and new location.
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(85, 85, 45, 45).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  // layer's layer_property_changed_ should be considered as damage to render

[weiliangc, 2017/07/28 21:40:44]

nit: Layer's

[wutao, 2017/07/28 23:38:58]

Done.

+  // surface.
+  EXPECT_TRUE(GetRenderSurface(child)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 
   // With the anchor on the layer's center, now we can test the rotation more
   // intuitively, since it applies about the layer's anchor.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->SetTransformMutated(child->element_id(), rotation);
   EmulateDrawingOneFrame(root);
 
   // Since the child layer is square, rotation by 45 degrees about the center
   // should increase the size of the expected rect by sqrt(2), centered around
   // (100, 100). The old exposed region should be fully contained in the new
   // region.
   float expected_width = 30.f * sqrt(2.f);
   float expected_position = 100.f - 0.5f * expected_width;
   gfx::Rect expected_rect = gfx::ToEnclosingRect(gfx::RectF(
       expected_position, expected_position, expected_width, expected_width));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(expected_rect.ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  // Transform from browser animation should not be considered as damage from
+  // contributing layer since it is applied to the whole layer which has a
+  // render surface.
+  EXPECT_FALSE(GetRenderSurface(child)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForPerspectiveClippedLayer) {
   // If a layer has a perspective transform that causes w < 0, then not
   // clipping the layer can cause an invalid damage rect. This test checks that
   // the w < 0 case is tracked properly.
   //
   // The transform is constructed so that if w < 0 clipping is not performed,
   // the incorrect rect will be very small, specifically: position (500.972504,
   // 498.544617) and size 0.056610 x 2.910767.  Instead, the correctly
@@ skipping 34 matching lines @@
   EmulateDrawingOneFrame(root);
 
   // The expected damage should cover the entire root surface (500x500), but we
   // don't care whether the damage rect was clamped or is larger than the
   // surface for this test.
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   gfx::Rect damage_we_care_about = gfx::Rect(gfx::Size(500, 500));
   EXPECT_TRUE(root_damage_rect.Contains(damage_we_care_about));
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForBlurredSurface) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* surface = root->test_properties()->children[0];
   LayerImpl* child = surface->test_properties()->children[0];
 
   FilterOperations filters;
   filters.Append(FilterOperation::CreateBlurFilter(5.f));
 
-  // Setting the filter will damage the whole surface.
+  // Setting the filter will damage the whole surface, but not conrresponding
+  // render surface.
   ClearDamageForAllSurfaces(root);
   surface->test_properties()->filters = filters;
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(surface)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 
   // Setting the update rect should cause the corresponding damage to the
   // surface, blurred based on the size of the blur filter.
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(1, 2, 3, 4));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Damage position on the surface should be: position of update_rect (1, 2)
   // relative to the child (300, 300), but expanded by the blur outsets
   // (15, since the blur radius is 5).
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(286, 287, 33, 34), root_damage_rect);
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(surface)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForImageFilter) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
   gfx::Rect root_damage_rect, child_damage_rect;
 
   // Allow us to set damage on child too.
   child->SetDrawsContent(true);
 
   FilterOperations filters;
   filters.Append(FilterOperation::CreateReferenceFilter(
       SkBlurImageFilter::Make(2, 2, nullptr)));
 
   // Setting the filter will damage the whole surface.
-  ClearDamageForAllSurfaces(root);
   child->test_properties()->force_render_surface = true;
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
+  ClearDamageForAllSurfaces(root);
   child->layer_tree_impl()->SetFilterMutated(child->element_id(), filters);
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
 
   // gfx::Rect(100, 100, 30, 30), expanded by 6px for the 2px blur filter.
   EXPECT_EQ(gfx::Rect(94, 94, 42, 42), root_damage_rect);
 
   // gfx::Rect(0, 0, 30, 30), expanded by 6px for the 2px blur filter.
   EXPECT_EQ(gfx::Rect(-6, -6, 42, 42), child_damage_rect);
 
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+
   // CASE 1: Setting the update rect should damage the whole surface (for now)
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(1, 1));
   EmulateDrawingOneFrame(root);
 
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
 
   // gfx::Rect(100, 100, 1, 1), expanded by 6px for the 2px blur filter.
   EXPECT_EQ(gfx::Rect(94, 94, 13, 13), root_damage_rect);
 
   // gfx::Rect(0, 0, 1, 1), expanded by 6px for the 2px blur filter.
   EXPECT_EQ(gfx::Rect(-6, -6, 13, 13), child_damage_rect);
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForTransformedImageFilter) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
   gfx::Rect root_damage_rect, child_damage_rect;
 
   // Allow us to set damage on child too.
   child->SetDrawsContent(true);
 
@@ skipping 245 matching lines @@
   EmulateDrawingOneFrame(root);
 
   // Sanity check - all 3 layers should be on the same render surface; render
   // surfaces are tested elsewhere.
   ASSERT_EQ(3, GetRenderSurface(root)->num_contributors());
 
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(400, 380, 6, 8).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 
   // CASE 2: If the layer is removed, its entire old layer becomes exposed, not
   //         just the last update rect.
 
   // Advance one frame without damage so that we know the damage rect is not
   // leftover from the previous case.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(root_damage_rect.IsEmpty());
 
   // Then, test removing child1.
   root->test_properties()->RemoveChild(child1);
   child1 = NULL;
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(100, 100, 30, 30).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForNewUnchangedLayer) {
   // If child2 is added to the layer tree, but it doesn't have any explicit
   // damage of its own, it should still indeed damage the target surface.
 
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
 
   ClearDamageForAllSurfaces(root);
   {
@@ skipping 16 matching lines @@
   EmulateDrawingOneFrame(root);
 
   // Sanity check - all 3 layers should be on the same render surface; render
   // surfaces are tested elsewhere.
   ASSERT_EQ(3, GetRenderSurface(root)->num_contributors());
 
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(400, 380, 6, 8).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForMultipleLayers) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child1 = root->test_properties()->children[0];
 
   // In this test we don't want the above tree manipulation to be considered
   // part of the same frame.
   ClearDamageForAllSurfaces(root);
   {
@@ skipping 14 matching lines @@
   ClearDamageForAllSurfaces(root);
   child1->SetUpdateRect(gfx::Rect(1, 2));
   child2->SetUpdateRect(gfx::Rect(3, 4));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(100, 100, 303, 284).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForNestedSurfaces) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* child1 = root->test_properties()->children[0];
   LayerImpl* child2 = root->test_properties()->children[1];
   LayerImpl* grand_child1 =
       root->test_properties()->children[0]->test_properties()->children[0];
   child2->test_properties()->force_render_surface = true;
   grand_child1->test_properties()->force_render_surface = true;
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   gfx::Rect child_damage_rect;
   gfx::Rect root_damage_rect;
 
   // CASE 1: Damage to a descendant surface should propagate properly to
   //         ancestor surface.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->SetOpacityMutated(grand_child1->element_id(), 0.5f);
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(200, 200, 6, 8).ToString(), child_damage_rect.ToString());
   EXPECT_EQ(gfx::Rect(300, 300, 6, 8).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child2)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(grand_child1)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 
   // CASE 2: Same as previous case, but with additional damage elsewhere that
   //         should be properly unioned.
   // - child1 surface damage in root surface space:
   //   gfx::Rect(300, 300, 6, 8);
   // - child2 damage in root surface space:
   //   gfx::Rect(11, 11, 18, 18);
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->SetOpacityMutated(grand_child1->element_id(), 0.7f);
   root->layer_tree_impl()->SetOpacityMutated(child2->element_id(), 0.7f);
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(200, 200, 6, 8).ToString(), child_damage_rect.ToString());
   EXPECT_EQ(gfx::Rect(11, 11, 295, 297).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child2)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(grand_child1)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForSurfaceChangeFromDescendantLayer) {
   // If descendant layer changes and affects the content bounds of the render
   // surface, then the entire descendant surface should be damaged, and it
   // should damage its ancestor surface with the old and new surface regions.
 
   // This is a tricky case, since only the first grand_child changes, but the
   // entire surface should be marked dirty.
 
@@ skipping 16 matching lines @@
   // The new surface bounds should be damaged entirely, even though only one of
   // the layers changed.
   EXPECT_EQ(gfx::Rect(190, 190, 11, 23).ToString(),
             child_damage_rect.ToString());
 
   // Damage to the root surface should be the union of child1's *entire* render
   // surface (in target space), and its old exposed area (also in target
   // space).
   EXPECT_EQ(gfx::Rect(290, 290, 16, 23).ToString(),
             root_damage_rect.ToString());
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForSurfaceChangeFromAncestorLayer) {
   // An ancestor/owning layer changes that affects the position/transform of
   // the render surface. Note that in this case, the layer_property_changed flag
   // already propagates to the subtree (tested in LayerImpltest), which damages
   // the entire child1 surface, but the damage tracker still needs the correct
   // logic to compute the exposed region on the root surface.
 
   // TODO(shawnsingh): the expectations of this test case should change when we
@@ skipping 20 matching lines @@
   // The new surface bounds should be damaged entirely.
   EXPECT_EQ(gfx::Rect(190, 190, 16, 18).ToString(),
             child_damage_rect.ToString());
 
   // The entire child1 surface and the old exposed child1 surface should damage
   // the root surface.
   //  - old child1 surface in target space: gfx::Rect(290, 290, 16, 18)
   //  - new child1 surface in target space: gfx::Rect(240, 240, 16, 18)
   EXPECT_EQ(gfx::Rect(240, 240, 66, 68).ToString(),
             root_damage_rect.ToString());
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child1)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForAddingAndRemovingRenderSurfaces) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* child1 = root->test_properties()->children[0];
   gfx::Rect child_damage_rect;
   gfx::Rect root_damage_rect;
 
   // CASE 1: If a descendant surface disappears, its entire old area becomes
   //         exposed.
   ClearDamageForAllSurfaces(root);
   child1->test_properties()->force_render_surface = false;
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Sanity check that there is only one surface now.
   ASSERT_EQ(GetRenderSurface(child1), GetRenderSurface(root));
   ASSERT_EQ(4, GetRenderSurface(root)->num_contributors());
 
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(290, 290, 16, 18).ToString(),
             root_damage_rect.ToString());
 
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+
   // CASE 2: If a descendant surface appears, its entire old area becomes
   //         exposed.
 
   // Cycle one frame of no change, just to sanity check that the next rect is
   // not because of the old damage state.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
@@ skipping 12 matching lines @@
   EXPECT_EQ(2, GetRenderSurface(child1)->num_contributors());
 
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(190, 190, 16, 18).ToString(),
             child_damage_rect.ToString());
   EXPECT_EQ(gfx::Rect(290, 290, 16, 18).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyNoDamageWhenNothingChanged) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* child1 = root->test_properties()->children[0];
   gfx::Rect child_damage_rect;
   gfx::Rect root_damage_rect;
 
   // CASE 1: If nothing changes, the damage rect should be empty.
   //
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(child_damage_rect.IsEmpty());
   EXPECT_TRUE(root_damage_rect.IsEmpty());
+  EXPECT_FALSE(GetRenderSurface(root)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 
   // CASE 2: If nothing changes twice in a row, the damage rect should still be
   //         empty.
   //
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(child_damage_rect.IsEmpty());
   EXPECT_TRUE(root_damage_rect.IsEmpty());
+  EXPECT_FALSE(GetRenderSurface(root)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyNoDamageForUpdateRectThatDoesNotDrawContent) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* child1 = root->test_properties()->children[0];
   gfx::Rect child_damage_rect;
   gfx::Rect root_damage_rect;
 
   // In our specific tree, the update rect of child1 should not cause any
   // damage to any surface because it does not actually draw content.
   ClearDamageForAllSurfaces(root);
   child1->SetUpdateRect(gfx::Rect(1, 2));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(child_damage_rect.IsEmpty());
   EXPECT_TRUE(root_damage_rect.IsEmpty());
+  EXPECT_FALSE(GetRenderSurface(root)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageForMask) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   // In the current implementation of the damage tracker, changes to mask
   // layers should damage the entire corresponding surface.
 
   ClearDamageForAllSurfaces(root);
@@ skipping 26 matching lines @@
   //         surface.
   ClearDamageForAllSurfaces(root);
   mask_layer->SetUpdateRect(gfx::Rect(1, 2, 3, 4));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   gfx::Rect child_damage_rect;
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_EQ(gfx::Rect(30, 30).ToString(), child_damage_rect.ToString());
 
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+
   // CASE 2: a property change on the mask layer should damage the entire
   //         target surface.
 
   // Advance one frame without damage so that we know the damage rect is not
   // leftover from the previous case.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(child_damage_rect.IsEmpty());
 
   // Then test the property change.
   ClearDamageForAllSurfaces(root);
   mask_layer->NoteLayerPropertyChanged();
 
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_EQ(gfx::Rect(30, 30).ToString(), child_damage_rect.ToString());
 
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_FALSE(GetRenderSurface(child)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
+
   // CASE 3: removing the mask also damages the entire target surface.
   //
 
   // Advance one frame without damage so that we know the damage rect is not
   // leftover from the previous case.
   ClearDamageForAllSurfaces(root);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_TRUE(child_damage_rect.IsEmpty());
 
   // Then test mask removal.
   ClearDamageForAllSurfaces(root);
   child->test_properties()->SetMaskLayer(nullptr);
   child->NoteLayerPropertyChanged();
   ASSERT_TRUE(child->LayerPropertyChanged());
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Sanity check that a render surface still exists.
   ASSERT_TRUE(GetRenderSurface(child));
 
   EXPECT_TRUE(GetRenderSurface(child)->damage_tracker()->GetDamageRectIfValid(
       &child_damage_rect));
   EXPECT_EQ(gfx::Rect(30, 30).ToString(), child_damage_rect.ToString());
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, DamageWhenAddedExternally) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   // Case 1: This test ensures that when the tracker is given damage, that
   //         it is included with any other partial damage.
   //
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(10, 11, 12, 13));
   GetRenderSurface(root)->damage_tracker()->AddDamageNextUpdate(
       gfx::Rect(15, 16, 32, 33));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::UnionRects(gfx::Rect(15, 16, 32, 33),
                             gfx::Rect(100 + 10, 100 + 11, 12, 13)).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 
   // Case 2: An additional sanity check that adding damage works even when
   //         nothing on the layer tree changed.
   //
   ClearDamageForAllSurfaces(root);
   GetRenderSurface(root)->damage_tracker()->AddDamageNextUpdate(
       gfx::Rect(30, 31, 14, 15));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(30, 31, 14, 15).ToString(), root_damage_rect.ToString());
+  EXPECT_FALSE(GetRenderSurface(root)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageWithNoContributingLayers) {
   std::unique_ptr<LayerImpl> root =
       LayerImpl::Create(host_impl_.active_tree(), 1);
   root->test_properties()->force_render_surface = true;
   host_impl_.active_tree()->SetRootLayerForTesting(std::move(root));
   LayerImpl* root_ptr = host_impl_.active_tree()->root_layer_for_testing();
   root_ptr->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root_ptr);
 
   DCHECK_EQ(GetRenderSurface(root_ptr), root_ptr->render_target());
   RenderSurfaceImpl* target_surface = GetRenderSurface(root_ptr);
   gfx::Rect damage_rect;
   EXPECT_TRUE(
       target_surface->damage_tracker()->GetDamageRectIfValid(&damage_rect));
   EXPECT_TRUE(damage_rect.IsEmpty());
+  EXPECT_FALSE(GetRenderSurface(root_ptr)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, VerifyDamageAccumulatesUntilReset) {
   // If damage is not cleared, it should accumulate.
 
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface();
   LayerImpl* child = root->test_properties()->children[0];
 
   ClearDamageForAllSurfaces(root);
   child->SetUpdateRect(gfx::Rect(10.f, 11.f, 1.f, 2.f));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
 
   // Sanity check damage after the first frame; this isnt the actual test yet.
   gfx::Rect root_damage_rect;
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(110, 111, 1, 2).ToString(), root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 
   // New damage, without having cleared the previous damage, should be unioned
   // to the previous one.
   child->SetUpdateRect(gfx::Rect(20, 25, 1, 2));
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_EQ(gfx::Rect(110, 111, 11, 16).ToString(),
             root_damage_rect.ToString());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 
   // If we notify the damage tracker that we drew the damaged area, then damage
   // should be emptied.
   GetRenderSurface(root)->damage_tracker()->DidDrawDamagedArea();
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(root_damage_rect.IsEmpty());
+  EXPECT_FALSE(GetRenderSurface(root)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 
   // Damage should remain empty even after one frame, since there's yet no new
   // damage.
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   EmulateDrawingOneFrame(root);
   EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &root_damage_rect));
   EXPECT_TRUE(root_damage_rect.IsEmpty());
+  EXPECT_FALSE(GetRenderSurface(root)
+                   ->damage_tracker()
+                   ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, HugeDamageRect) {
   // This number is so large that we start losting floating point accuracy.
   const int kBigNumber = 900000000;
   // Walk over a range to find floating point inaccuracy boundaries that move
   // toward the wrong direction.
   const int kRange = 5000;
 
   for (int i = 0; i < kRange; ++i) {
@@ skipping 16 matching lines @@
     EmulateDrawingOneFrame(root, device_scale_factor);
 
     // The expected damage should cover the visible part of the child layer,
     // which is (0, 0, i, i) in the viewport.
     gfx::Rect root_damage_rect;
     EXPECT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
         &root_damage_rect));
     gfx::Rect damage_we_care_about = gfx::Rect(i, i);
     EXPECT_LE(damage_we_care_about.right(), root_damage_rect.right());
     EXPECT_LE(damage_we_care_about.bottom(), root_damage_rect.bottom());
+    EXPECT_TRUE(GetRenderSurface(root)
+                    ->damage_tracker()
+                    ->has_damage_from_contributing_content());
   }
 }
 
 TEST_F(DamageTrackerTest, DamageRectTooBig) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface(2);
   LayerImpl* child1 = root->test_properties()->children[0];
   LayerImpl* child2 = root->test_properties()->children[1];
 
   // Really far left.
   child1->SetPosition(gfx::PointF(std::numeric_limits<int>::min() + 100, 0));
   child1->SetBounds(gfx::Size(1, 1));
 
   // Really far right.
   child2->SetPosition(gfx::PointF(std::numeric_limits<int>::max() - 100, 0));
   child2->SetBounds(gfx::Size(1, 1));
 
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   float device_scale_factor = 1.f;
   EmulateDrawingOneFrame(root, device_scale_factor);
 
   // The expected damage would be too large to store in a gfx::Rect, so we
   // should damage everything (ie, we don't have a valid rect).
   gfx::Rect damage_rect;
   EXPECT_FALSE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_EQ(GetRenderSurface(root)->content_rect(),
             GetRenderSurface(root)->GetDamageRect());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, DamageRectTooBigWithFilter) {
   LayerImpl* root = CreateAndSetUpTestTreeWithOneSurface(2);
   LayerImpl* child1 = root->test_properties()->children[0];
   LayerImpl* child2 = root->test_properties()->children[1];
 
   FilterOperations filters;
   filters.Append(FilterOperation::CreateBlurFilter(5.f));
   root->SetDrawsContent(true);
@@ skipping 11 matching lines @@
   float device_scale_factor = 1.f;
   EmulateDrawingOneFrame(root, device_scale_factor);
 
   // The expected damage would be too large to store in a gfx::Rect, so we
   // should damage everything (ie, we don't have a valid rect).
   gfx::Rect damage_rect;
   EXPECT_FALSE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_EQ(GetRenderSurface(root)->content_rect(),
             GetRenderSurface(root)->GetDamageRect());
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, DamageRectTooBigInRenderSurface) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* child1 = root->test_properties()->children[0];
   LayerImpl* grandchild1 = child1->test_properties()->children[0];
   LayerImpl* grandchild2 = child1->test_properties()->children[1];
 
   // Really far left.
   grandchild1->SetPosition(
@@ skipping 28 matching lines @@
 
   // However, the root should just use the child1 render surface's content rect
   // as damage.
   ASSERT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_TRUE(damage_rect.Contains(GetRenderSurface(root)->content_rect()));
   EXPECT_TRUE(damage_rect.Contains(
       gfx::ToEnclosingRect(GetRenderSurface(child1)->DrawableContentRect())));
   EXPECT_EQ(damage_rect, GetRenderSurface(root)->GetDamageRect());
 
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+
   // Add new damage, without changing properties, which goes down a different
   // path in the damage tracker.
   root->layer_tree_impl()->ResetAllChangeTracking();
   grandchild1->AddDamageRect(gfx::Rect(grandchild1->bounds()));
   grandchild2->AddDamageRect(gfx::Rect(grandchild1->bounds()));
 
   // Recompute all damage / properties.
   render_surface_list.clear();
   ExecuteCalculateDrawProperties(root, device_scale_factor,
                                  &render_surface_list);
   DamageTracker::UpdateDamageTracking(host_impl_.active_tree(),
                                       render_surface_list);
 
   // Child1 should still not have a valid rect, since the union of the damage of
   // its children is not representable by a single rect.
   EXPECT_FALSE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_EQ(GetRenderSurface(child1)->content_rect(),
             GetRenderSurface(child1)->GetDamageRect());
 
   // Root should have valid damage and contain both its content rect and the
   // drawable content rect of child1.
   ASSERT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_TRUE(damage_rect.Contains(GetRenderSurface(root)->content_rect()));
   EXPECT_TRUE(damage_rect.Contains(
       gfx::ToEnclosingRect(GetRenderSurface(child1)->DrawableContentRect())));
   EXPECT_EQ(damage_rect, GetRenderSurface(root)->GetDamageRect());
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 TEST_F(DamageTrackerTest, DamageRectTooBigInRenderSurfaceWithFilter) {
   LayerImpl* root = CreateAndSetUpTestTreeWithTwoSurfaces();
   LayerImpl* child1 = root->test_properties()->children[0];
   LayerImpl* grandchild1 = child1->test_properties()->children[0];
   LayerImpl* grandchild2 = child1->test_properties()->children[1];
 
   // Set up a moving pixels filter on the child.
   FilterOperations filters;
@@ skipping 34 matching lines @@
 
   // However, the root should just use the child1 render surface's content rect
   // as damage.
   ASSERT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_TRUE(damage_rect.Contains(GetRenderSurface(root)->content_rect()));
   EXPECT_TRUE(damage_rect.Contains(
       gfx::ToEnclosingRect(GetRenderSurface(child1)->DrawableContentRect())));
   EXPECT_EQ(damage_rect, GetRenderSurface(root)->GetDamageRect());
 
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+
   // Add new damage, without changing properties, which goes down a different
   // path in the damage tracker.
   root->layer_tree_impl()->ResetAllChangeTracking();
   grandchild1->AddDamageRect(gfx::Rect(grandchild1->bounds()));
   grandchild2->AddDamageRect(gfx::Rect(grandchild1->bounds()));
 
   // Recompute all damage / properties.
   render_surface_list.clear();
   ExecuteCalculateDrawProperties(root, device_scale_factor,
                                  &render_surface_list);
   DamageTracker::UpdateDamageTracking(host_impl_.active_tree(),
                                       render_surface_list);
 
   // Child1 should still not have a valid rect, since the union of the damage of
   // its children is not representable by a single rect.
   EXPECT_FALSE(GetRenderSurface(child1)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_EQ(GetRenderSurface(child1)->content_rect(),
             GetRenderSurface(child1)->GetDamageRect());
 
   // Root should have valid damage and contain both its content rect and the
   // drawable content rect of child1.
   ASSERT_TRUE(GetRenderSurface(root)->damage_tracker()->GetDamageRectIfValid(
       &damage_rect));
   EXPECT_TRUE(damage_rect.Contains(GetRenderSurface(root)->content_rect()));
   EXPECT_TRUE(damage_rect.Contains(
       gfx::ToEnclosingRect(GetRenderSurface(child1)->DrawableContentRect())));
   EXPECT_EQ(damage_rect, GetRenderSurface(root)->GetDamageRect());
+
+  EXPECT_TRUE(GetRenderSurface(root)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
+  EXPECT_TRUE(GetRenderSurface(child1)
+                  ->damage_tracker()
+                  ->has_damage_from_contributing_content());
 }
 
 }  // namespace
 }  // namespace cc