Delete layout_viewport_size.

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index bc9acf5a9e2df5015736e5859b98110e4c496ce4..71da21bc0c9b72be0aabd9467f0147121242c96b 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -520,10 +520,6 @@ gfx::Size LayerTreeImpl::device_viewport_size() const {
   return layer_tree_host_impl_->device_viewport_size();
 }
 
-gfx::Size LayerTreeImpl::layout_viewport_size() const {
-  return layer_tree_host_impl_->layout_viewport_size();
-}
-
 std::string LayerTreeImpl::layer_tree_as_text() const {
   return layer_tree_host_impl_->LayerTreeAsText();
 }