Fix UpdateTilePriorities viewport in Android WebView.

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 686efc3695cdabacd36546ffaeb97d6db6c51db5..0f0517f03335a70010809b3a06237d15e80a836b 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -4917,6 +4917,9 @@ class TestRenderer : public GLRenderer, public RendererClient {
   virtual gfx::Rect DeviceViewport() const OVERRIDE {
     return gfx::Rect(viewport_size_);
   }
+  virtual gfx::Rect DeviceClip() const OVERRIDE {
+    return DeviceViewport();
+  }
   virtual float DeviceScaleFactor() const OVERRIDE {
     return 1.f;
   }
@@ -5352,7 +5355,7 @@ TEST_F(LayerTreeHostImplTestWithDelegatingRenderer, FrameIncludesDamageRect) {
   host_impl_->active_tree()->SetRootLayer(root.PassAs<LayerImpl>());
 
   // Draw a frame. In the first frame, the entire viewport should be damaged.
-  gfx::Rect full_frame_damage = gfx::Rect(host_impl_->device_viewport_size());
+  gfx::Rect full_frame_damage = host_impl_->DeviceViewport();
   DrawFrameAndTestDamage(full_frame_damage);
 
   // The second frame has damage that doesn't touch the child layer. Its quads