Update the nine patch layer to use UI resources

cc/trees/layer_tree_host.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.h"
 
 #include <algorithm>
 #include <stack>
 
 #include "base/bind.h"
@@ skipping 1123 matching lines @@
          ui_resource_client_map_.end());
 
   request.bitmap = client->GetBitmap(request.id, resource_lost);
   ui_resource_request_queue_.push_back(request);
   ui_resource_client_map_[request.id] = client;
   return request.id;
 }
 
 // Deletes a UI resource.  May safely be called more than once.
 void LayerTreeHost::DeleteUIResource(UIResourceId uid) {
-  UIResourceClientMap::iterator iter = ui_resource_client_map_.find(uid);
-  if (iter == ui_resource_client_map_.end())
+  UIResourceClientMap::iterator it = ui_resource_client_map_.find(uid);
+  if (it == ui_resource_client_map_.end())
     return;
 
   UIResourceRequest request;
   request.type = UIResourceRequest::UIResourceDelete;
   request.id = uid;
   ui_resource_request_queue_.push_back(request);
   ui_resource_client_map_.erase(uid);
 }
 
+// Returns the size of a resource given its id.
+gfx::Size LayerTreeHost::GetUIResourceSize(UIResourceId uid) {
+  UIResourceClientMap::iterator it = ui_resource_client_map_.find(uid);
+  if (it == ui_resource_client_map_.end())
+    return gfx::Size();
+
+  DCHECK(it->second);
+
+  bool resource_lost = false;
+  UIResourceClient* client = it->second;
+  scoped_refptr<UIResourceBitmap> bitmap =
+      client->GetBitmap(uid, resource_lost);

[aelias_OOO_until_Jul13, 2013/08/30 06:20:41]

This operation may be expensive, I don't think we should call it for a
cheap-sounding getter.  Could you store a struct in the client_map_ instead
containing the size as well as the pointer?

[powei, 2013/09/03 23:36:05]

Done.

+
+  DCHECK(bitmap.get());
+
+  return bitmap->GetSize();
+}
+
 void LayerTreeHost::UIResourceLost(UIResourceId uid) {
-  UIResourceClientMap::iterator iter = ui_resource_client_map_.find(uid);
-  if (iter == ui_resource_client_map_.end())
+  UIResourceClientMap::iterator it = ui_resource_client_map_.find(uid);
+  if (it == ui_resource_client_map_.end())
     return;
 
   UIResourceRequest request;
   bool resource_lost = true;
   request.type = UIResourceRequest::UIResourceCreate;
   request.id = uid;
-  request.bitmap = iter->second->GetBitmap(uid, resource_lost);
+  request.bitmap = it->second->GetBitmap(uid, resource_lost);
   DCHECK(request.bitmap.get());
   ui_resource_request_queue_.push_back(request);
 }
 
 void LayerTreeHost::DidLoseUIResources() {
   // When output surface is lost, we need to recreate the resource.
-  for (UIResourceClientMap::iterator iter = ui_resource_client_map_.begin();
-       iter != ui_resource_client_map_.end();
-       ++iter) {
-    UIResourceLost(iter->first);
+  for (UIResourceClientMap::iterator it = ui_resource_client_map_.begin();
+       it != ui_resource_client_map_.end();
+       ++it) {
+    UIResourceLost(it->first);
   }
 }
 
 }  // namespace cc