Prevent recreation of UI resource holder when created with resource ID

cc/layers/ui_resource_layer.cc

Index: cc/layers/ui_resource_layer.cc
diff --git a/cc/layers/ui_resource_layer.cc b/cc/layers/ui_resource_layer.cc
index 944cf7d54844c7016feb32eacfc401fb590146ab..22bc26212c586959f187a6f255c7c94f886c312e 100644
--- a/cc/layers/ui_resource_layer.cc
+++ b/cc/layers/ui_resource_layer.cc
@@ -41,6 +41,8 @@ class SharedUIResourceHolder : public UIResourceLayer::UIResourceHolder {
 
   UIResourceId id() override { return id_; }
 
+  bool NeedsRecreation() override { return true; }
+
  private:
   explicit SharedUIResourceHolder(UIResourceId id) : id_(id) {}
 
@@ -51,6 +53,10 @@ class SharedUIResourceHolder : public UIResourceLayer::UIResourceHolder {
 
 UIResourceLayer::UIResourceHolder::~UIResourceHolder() {}
 
+bool UIResourceLayer::UIResourceHolder::NeedsRecreation() {
+  return false;
+}
+
 scoped_refptr<UIResourceLayer> UIResourceLayer::Create() {
   return make_scoped_refptr(new UIResourceLayer());
 }
@@ -112,10 +118,15 @@ void UIResourceLayer::SetLayerTreeHost(LayerTreeHost* host) {
 }
 
 void UIResourceLayer::RecreateUIResourceHolder() {
-  ui_resource_holder_ = nullptr;
   if (layer_tree_host() && !bitmap_.empty()) {
     ui_resource_holder_ =
         ScopedUIResourceHolder::Create(layer_tree_host(), bitmap_);
+  } else if (ui_resource_holder_.get() &&
+             ui_resource_holder_->NeedsRecreation()) {
+    ui_resource_holder_ =

[awoloszyn, 2014/10/24 14:15:13]

We should be able to do nothing in this case, since SharedUIResourceHolder just
contains an id (integer), destroying and re-creating it seem un-necessary.

[Changwan Ryu, 2014/10/27 00:57:37]

Done.

+        SharedUIResourceHolder::Create(ui_resource_holder_->id());
+  } else {
+    ui_resource_holder_ = nullptr;
   }
   UpdateDrawsContent(HasDrawableContent());
 }