cc: Resize picture layer tiling set during commit

cc/picture_layer_tiling_set.cc

Index: cc/picture_layer_tiling_set.cc
diff --git a/cc/picture_layer_tiling_set.cc b/cc/picture_layer_tiling_set.cc
index e435a1001c406d4a43ae85ef1f1f7dbce4d37866..4ec2e70b1d879f7d68b1a5e39fbf7dc4297837cb 100644
--- a/cc/picture_layer_tiling_set.cc
+++ b/cc/picture_layer_tiling_set.cc
@@ -24,6 +24,8 @@ void PictureLayerTilingSet::CloneFrom(const PictureLayerTilingSet& other) {
 }
 
 void PictureLayerTilingSet::SetLayerBounds(gfx::Size layer_bounds) {
+  if (layer_bounds_ == layer_bounds)
+    return;
   layer_bounds_ = layer_bounds;
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->SetLayerBounds(layer_bounds);