cc : Update render surfaces using LayerListIterator instead of treewalk

cc/test/layer_tree_host_common_test.cc

Index: cc/test/layer_tree_host_common_test.cc
diff --git a/cc/test/layer_tree_host_common_test.cc b/cc/test/layer_tree_host_common_test.cc
index d1a7dc25b643183735a62b201ebc499b174bd117..9d62ce2c79dfa375cae390b463e8dbb8dbf76197 100644
--- a/cc/test/layer_tree_host_common_test.cc
+++ b/cc/test/layer_tree_host_common_test.cc
@@ -167,7 +167,8 @@ void LayerTreeHostCommonTestBase::ExecuteCalculateDrawProperties(
     bool can_use_lcd_text,
     bool layers_always_allowed_lcd_text) {
   host_impl()->active_tree()->SetDeviceScaleFactor(device_scale_factor);
-  host_impl()->active_tree()->SetPageScaleOnActiveTree(page_scale_factor);
+  if (host_impl()->active_tree()->property_trees()->needs_rebuild)

[ajuma, 2016/03/22 14:41:54]

Why does this depend on whether we need to rebuild?

[jaydasika, 2016/03/22 20:48:34]

Whoops, it should be the other way around, if we are going to build property
trees, we don't need to update page scale factor as property tree builder will
take care of it. Will remove this anyway as there is  no harm in doing it twice.

+    host_impl()->active_tree()->SetPageScaleOnActiveTree(page_scale_factor);
 
   gfx::Transform identity_matrix;
   gfx::Size device_viewport_size =