cc: Allow the main thread to cancel commits

cc/trees/layer_tree_host_unittest_animation.cc

Index: cc/trees/layer_tree_host_unittest_animation.cc
diff --git a/cc/trees/layer_tree_host_unittest_animation.cc b/cc/trees/layer_tree_host_unittest_animation.cc
index fa4b88632b366eb61b42e1ec4be1cec63d25e3c9..171c155576f3f21586e43e211bb375148fa7f9ac 100644
--- a/cc/trees/layer_tree_host_unittest_animation.cc
+++ b/cc/trees/layer_tree_host_unittest_animation.cc
@@ -18,9 +18,32 @@
 namespace cc {
 namespace {
 
+class AlwaysUpdateLayer : public Layer {
+ public:
+  static scoped_refptr<AlwaysUpdateLayer> Create() {
+    return new AlwaysUpdateLayer();
+  }
+
+  virtual bool DrawsContent() const OVERRIDE { return true; }
+  virtual bool Update(ResourceUpdateQueue* queue,
+                      const OcclusionTracker* occlusion) OVERRIDE {
+    return true;
+  }
+
+ private:
+  AlwaysUpdateLayer() {}
+  virtual ~AlwaysUpdateLayer() {}
+};
+
 class LayerTreeHostAnimationTest : public LayerTreeTest {
  public:
   virtual void SetupTree() OVERRIDE {
+    scoped_refptr<AlwaysUpdateLayer> root_layer = AlwaysUpdateLayer::Create();
+    root_layer->SetBounds(gfx::Size(1, 1));
+    root_layer->SetIsDrawable(true);
+    root_layer->SetScrollable(true);
+    layer_tree_host()->SetRootLayer(root_layer);
+
     LayerTreeTest::SetupTree();
     layer_tree_host()->root_layer()->set_layer_animation_delegate(this);
   }
@@ -445,9 +468,9 @@ class LayerTreeHostAnimationTestDoNotSkipLayersWithAnimatedOpacity
   }
 
   virtual void SetupTree() OVERRIDE {
-    update_check_layer_->SetOpacity(0.f);
-    layer_tree_host()->SetRootLayer(update_check_layer_);
     LayerTreeHostAnimationTest::SetupTree();
+    update_check_layer_->SetOpacity(0.f);
+    layer_tree_host()->root_layer()->AddChild(update_check_layer_);
   }
 
   virtual void BeginTest() OVERRIDE {
@@ -455,23 +478,25 @@ class LayerTreeHostAnimationTestDoNotSkipLayersWithAnimatedOpacity
   }
 
   virtual void DidActivateTreeOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
+    LayerImpl* update_check_layer_impl =
+        host_impl->active_tree()->LayerById(update_check_layer_->id());
     LayerAnimationController* controller_impl =
-        host_impl->active_tree()->root_layer()->layer_animation_controller();
+        update_check_layer_impl->layer_animation_controller();
     Animation* animation_impl =
         controller_impl->GetAnimation(Animation::Opacity);
     controller_impl->RemoveAnimation(animation_impl->id());
     EndTest();
   }
 
-  virtual void AfterTest() OVERRIDE {
+  virtual void DidCommit() OVERRIDE {
     // Update() should have been called once, proving that the layer was not
     // skipped.
     EXPECT_EQ(1u, update_check_layer_->update_count());
-
-    // clear update_check_layer_ so LayerTreeHost dies.
-    update_check_layer_ = NULL;
+    update_check_layer_->reset_update_count();
   }
 
+  virtual void AfterTest() OVERRIDE {}
+
  private:
   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> update_check_layer_;