cc: Move tracking of layer_property_changed to main thread (3)

cc/trees/layer_tree_host_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/layer_tree_host.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 3260 matching lines @@
   size_t expected_push_properties_grandchild3_;
 };
 
 class LayerTreeHostTestPushPropertiesAddingToTreeRequiresPush
     : public LayerTreeHostTestCasePushPropertiesThreeGrandChildren {
  protected:
   void DidCommitAndDrawFrame() override {
     int last_source_frame_number = layer_tree_host()->source_frame_number() - 1;
     switch (last_source_frame_number) {
       case 0:
+        // All layers except root will need push properties as they are added
+        // as a child to some other layer which changes their stacking order.
         EXPECT_FALSE(root_->needs_push_properties());
-        EXPECT_FALSE(root_->descendant_needs_push_properties());
-        EXPECT_FALSE(child_->needs_push_properties());
-        EXPECT_FALSE(child_->descendant_needs_push_properties());
-        EXPECT_FALSE(grandchild1_->needs_push_properties());
-        EXPECT_FALSE(grandchild1_->descendant_needs_push_properties());
-        EXPECT_FALSE(grandchild2_->needs_push_properties());
-        EXPECT_FALSE(grandchild2_->descendant_needs_push_properties());
-        EXPECT_FALSE(grandchild3_->needs_push_properties());
-        EXPECT_FALSE(grandchild3_->descendant_needs_push_properties());
-
-        layer_tree_host()->SetRootLayer(root_);
-
-        EXPECT_TRUE(root_->needs_push_properties());
         EXPECT_TRUE(root_->descendant_needs_push_properties());
         EXPECT_TRUE(child_->needs_push_properties());
         EXPECT_TRUE(child_->descendant_needs_push_properties());
         EXPECT_TRUE(grandchild1_->needs_push_properties());
         EXPECT_FALSE(grandchild1_->descendant_needs_push_properties());
         EXPECT_TRUE(grandchild2_->needs_push_properties());
         EXPECT_FALSE(grandchild2_->descendant_needs_push_properties());
         EXPECT_TRUE(grandchild3_->needs_push_properties());
         EXPECT_FALSE(grandchild3_->descendant_needs_push_properties());
+
+        layer_tree_host()->SetRootLayer(root_);
+
+        // Now, even the root will need to push properties.
+        EXPECT_TRUE(root_->needs_push_properties());
+        EXPECT_TRUE(root_->descendant_needs_push_properties());
         break;
       case 1:
         EndTest();
         break;
     }
   }
 };
 
 MULTI_THREAD_TEST_F(LayerTreeHostTestPushPropertiesAddingToTreeRequiresPush);
 
@@ skipping 3293 matching lines @@
     EndTest();
   }
 
   void AfterTest() override {}
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestPaintedDeviceScaleFactor);
 
 }  // namespace
 }  // namespace cc