[cc] Consolidate UI resource destruction and recreation

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
@@ skipping 1545 matching lines @@
 }
 
 void LayerTreeHostImpl::ReleaseTreeResources() {
   if (active_tree_->root_layer())
     SendReleaseResourcesRecursive(active_tree_->root_layer());
   if (pending_tree_ && pending_tree_->root_layer())
     SendReleaseResourcesRecursive(pending_tree_->root_layer());
   if (recycle_tree_ && recycle_tree_->root_layer())
     SendReleaseResourcesRecursive(recycle_tree_->root_layer());
 
-  // Remove all existing maps from UIResourceId to ResourceId.
-  ui_resource_map_.clear();
+  DeleteAllUIResources();
 }
 
 void LayerTreeHostImpl::CreateAndSetRenderer(
     OutputSurface* output_surface,
     ResourceProvider* resource_provider,
     bool skip_gl_renderer) {
   DCHECK(!renderer_);
   if (output_surface->capabilities().delegated_rendering) {
     renderer_ =
         DelegatingRenderer::Create(this, output_surface, resource_provider);
@@ skipping 990 matching lines @@
 }
 
 void LayerTreeHostImpl::DeleteUIResource(UIResourceId uid) {
   ResourceProvider::ResourceId id = ResourceIdForUIResource(uid);
   if (id) {
     resource_provider_->DeleteResource(id);
     ui_resource_map_.erase(uid);
   }
 }
 
+void LayerTreeHostImpl::DeleteAllUIResources() {
+  for (UIResourceMap::const_iterator iter = ui_resource_map_.begin();
+      iter != ui_resource_map_.end();
+      ++iter) {
+    resource_provider_->DeleteResource(iter->second);
+  }
+  ui_resource_map_.clear();
+}
+
 ResourceProvider::ResourceId LayerTreeHostImpl::ResourceIdForUIResource(
     UIResourceId uid) const {
   UIResourceMap::const_iterator iter = ui_resource_map_.find(uid);
   if (iter != ui_resource_map_.end())
     return iter->second;
   return 0;
 }
 
 }  // namespace cc