Fix UpdateTilePriorities viewport in Android WebView.

cc/test/fake_layer_tree_host_impl.h

Index: cc/test/fake_layer_tree_host_impl.h
diff --git a/cc/test/fake_layer_tree_host_impl.h b/cc/test/fake_layer_tree_host_impl.h
index da6ec41942769c4495d618a29cbdf2796f47b67b..b652a9168c14677c93d15d0a6435c87e899892a4 100644
--- a/cc/test/fake_layer_tree_host_impl.h
+++ b/cc/test/fake_layer_tree_host_impl.h
@@ -26,9 +26,14 @@ class FakeLayerTreeHostImpl : public LayerTreeHostImpl {
 
   virtual void CreatePendingTree() OVERRIDE;
 
+  virtual base::TimeTicks CurrentFrameTimeTicks() OVERRIDE;
+  void SetCurrentFrameTimeTicks(base::TimeTicks current_frame_time_ticks);
+
   using LayerTreeHostImpl::ActivatePendingTree;
+  using LayerTreeHostImpl::manage_tiles_needed;
 
  private:
+  base::TimeTicks current_frame_time_ticks_;
   FakeLayerTreeHostImplClient client_;
   FakeRenderingStatsInstrumentation stats_instrumentation_;
 };