Fix LayerTreeHostTestUndrawnLayersDamageLater flakiness

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 <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/synchronization/lock.h"
@@ skipping 556 matching lines @@
 
     gfx::RectF root_damage_rect;
     if (!frame_data->render_passes.empty())
       root_damage_rect = frame_data->render_passes.back()->damage_rect;
 
     // The first time, the whole view needs be drawn.
     // Afterwards, just the opacity of surface_layer1 is changed a few times,
     // and each damage should be the bounding box of it and its child. If this
     // was working improperly, the damage might not include its childs bounding
     // box.
-    // TODO(enne): This compositor thread function is asking for the
-    // frame number from the layer tree host on the main thread.  :(
-    switch (layer_tree_host()->source_frame_number()) {
-      case 1:
+    switch (host_impl->active_tree()->source_frame_number()) {
+      case 0:
         EXPECT_RECT_EQ(gfx::Rect(root_layer_->bounds()), root_damage_rect);
         break;
+      case 1:
       case 2:
       case 3:
-      case 4:
         EXPECT_RECT_EQ(gfx::Rect(child_layer_->bounds()), root_damage_rect);
         break;
       default:
         NOTREACHED();
     }
 
     return draw_result;
   }
 
   virtual void DidCommitAndDrawFrame() OVERRIDE {
@@ skipping 20 matching lines @@
 
   virtual void AfterTest() OVERRIDE {}
 
  private:
   FakeContentLayerClient client_;
   scoped_refptr<ContentLayer> root_layer_;
   scoped_refptr<FakeContentLayer> parent_layer_;
   scoped_refptr<FakeContentLayer> child_layer_;
 };
 
-// TODO(enne): http://crbug.com/380895
-// SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestUndrawnLayersDamageLater);
+SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestUndrawnLayersDamageLater);
 
 // Tests that if a layer is not drawn because of some reason in the parent,
 // causing its content bounds to not be computed, then when it is later drawn,
 // its content bounds get pushed.
 class LayerTreeHostTestUndrawnLayersPushContentBoundsLater
     : public LayerTreeHostTest {
  public:
   LayerTreeHostTestUndrawnLayersPushContentBoundsLater()
       : root_layer_(Layer::Create()) {}
 
@@ skipping 4256 matching lines @@
   const gfx::Size bounds_;
   FakeContentLayerClient client_;
   scoped_refptr<ContentLayerWithUpdateTracking> content_layer_;
   scoped_refptr<FakePictureLayer> picture_layer_;
   Layer* child_layer_;
 };
 
 MULTI_THREAD_TEST_F(LayerTreeHostTestContinuousPainting);
 
 }  // namespace cc