Update from https://crrev.com/320931

cc/trees/layer_tree_host_common_unittest.cc

Index: cc/trees/layer_tree_host_common_unittest.cc
diff --git a/cc/trees/layer_tree_host_common_unittest.cc b/cc/trees/layer_tree_host_common_unittest.cc
index d2c473e23d155fb143cda9b20cec2da08ba2a8f3..dd797d5b68ed09ac30015992a85dc7d74c9c465d 100644
--- a/cc/trees/layer_tree_host_common_unittest.cc
+++ b/cc/trees/layer_tree_host_common_unittest.cc
@@ -1006,6 +1006,8 @@ TEST_F(LayerTreeHostCommonTest, TransformsForFlatteningLayer) {
   scoped_refptr<Layer> child = Layer::Create();
   scoped_refptr<LayerWithForcedDrawsContent> grand_child =
       make_scoped_refptr(new LayerWithForcedDrawsContent());
+  scoped_refptr<LayerWithForcedDrawsContent> great_grand_child =
+      make_scoped_refptr(new LayerWithForcedDrawsContent());
 
   gfx::Transform rotation_about_y_axis;
   rotation_about_y_axis.RotateAboutYAxis(30.0);
@@ -1032,9 +1034,13 @@ TEST_F(LayerTreeHostCommonTest, TransformsForFlatteningLayer) {
                                gfx::Size(10, 10),
                                true,
                                false);
+  SetLayerPropertiesForTesting(great_grand_child.get(), identity_matrix,
+                               gfx::Point3F(), gfx::PointF(), gfx::Size(10, 10),
+                               true, false);
 
   root->AddChild(child);
   child->AddChild(grand_child);
+  grand_child->AddChild(great_grand_child);
   child->SetForceRenderSurface(true);
 
   scoped_ptr<FakeLayerTreeHost> host(CreateFakeLayerTreeHost());
@@ -1044,6 +1050,7 @@ TEST_F(LayerTreeHostCommonTest, TransformsForFlatteningLayer) {
   ASSERT_TRUE(root->should_flatten_transform());
   ASSERT_TRUE(child->should_flatten_transform());
   ASSERT_TRUE(grand_child->should_flatten_transform());
+  ASSERT_TRUE(great_grand_child->should_flatten_transform());
 
   gfx::Transform expected_child_draw_transform = rotation_about_y_axis;
   gfx::Transform expected_child_screen_space_transform = rotation_about_y_axis;
@@ -1053,6 +1060,10 @@ TEST_F(LayerTreeHostCommonTest, TransformsForFlatteningLayer) {
   flattened_rotation_about_y.FlattenTo2d();
   gfx::Transform expected_grand_child_screen_space_transform =
       flattened_rotation_about_y * rotation_about_y_axis;
+  gfx::Transform expected_great_grand_child_draw_transform =
+      flattened_rotation_about_y;
+  gfx::Transform expected_great_grand_child_screen_space_transform =
+      flattened_rotation_about_y * flattened_rotation_about_y;
 
   ExecuteCalculateDrawProperties(root.get());
 
@@ -1070,6 +1081,11 @@ TEST_F(LayerTreeHostCommonTest, TransformsForFlatteningLayer) {
                                   grand_child->draw_transform());
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected_grand_child_screen_space_transform,
                                   grand_child->screen_space_transform());
+  EXPECT_TRANSFORMATION_MATRIX_EQ(expected_great_grand_child_draw_transform,
+                                  great_grand_child->draw_transform());
+  EXPECT_TRANSFORMATION_MATRIX_EQ(
+      expected_great_grand_child_screen_space_transform,
+      great_grand_child->screen_space_transform());
 }
 
 TEST_F(LayerTreeHostCommonTest, TransformsForDegenerateIntermediateLayer) {
@@ -7015,6 +7031,27 @@ TEST_F(LayerTreeHostCommonTest, CanRenderToSeparateSurface) {
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
 
     EXPECT_EQ(2u, render_surface_layer_list.size());
+
+    int count_represents_target_render_surface = 0;
+    int count_represents_contributing_render_surface = 0;
+    int count_represents_itself = 0;
+    auto end = LayerIterator<LayerImpl>::End(&render_surface_layer_list);
+    for (auto it = LayerIterator<LayerImpl>::Begin(&render_surface_layer_list);
+         it != end; ++it) {
+      if (it.represents_target_render_surface())
+        count_represents_target_render_surface++;
+      if (it.represents_contributing_render_surface())
+        count_represents_contributing_render_surface++;
+      if (it.represents_itself())
+        count_represents_itself++;
+    }
+
+    // Two render surfaces.
+    EXPECT_EQ(2, count_represents_target_render_surface);
+    // Second render surface contributes to root render surface.
+    EXPECT_EQ(1, count_represents_contributing_render_surface);
+    // All 4 layers represent itself.
+    EXPECT_EQ(4, count_represents_itself);
   }
 
   {
@@ -7025,6 +7062,27 @@ TEST_F(LayerTreeHostCommonTest, CanRenderToSeparateSurface) {
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
 
     EXPECT_EQ(1u, render_surface_layer_list.size());
+
+    int count_represents_target_render_surface = 0;
+    int count_represents_contributing_render_surface = 0;
+    int count_represents_itself = 0;
+    auto end = LayerIterator<LayerImpl>::End(&render_surface_layer_list);
+    for (auto it = LayerIterator<LayerImpl>::Begin(&render_surface_layer_list);
+         it != end; ++it) {
+      if (it.represents_target_render_surface())
+        count_represents_target_render_surface++;
+      if (it.represents_contributing_render_surface())
+        count_represents_contributing_render_surface++;
+      if (it.represents_itself())
+        count_represents_itself++;
+    }
+
+    // Only root layer has a render surface.
+    EXPECT_EQ(1, count_represents_target_render_surface);
+    // No layer contributes a render surface to root render surface.
+    EXPECT_EQ(0, count_represents_contributing_render_surface);
+    // All 4 layers represent itself.
+    EXPECT_EQ(4, count_represents_itself);
   }
 }