Migrate Graphics2D to new design.

ppapi/host/ppapi_host.cc

Index: ppapi/host/ppapi_host.cc
diff --git a/ppapi/host/ppapi_host.cc b/ppapi/host/ppapi_host.cc
index 0ec37b6e11d2c8ac9ff5a7c96593a5420a1e310e..0934ed82c9a720a7dff5f41ae0494f59768aa5a6 100644
--- a/ppapi/host/ppapi_host.cc
+++ b/ppapi/host/ppapi_host.cc
@@ -136,23 +136,37 @@ void PpapiHost::OnHostMsgResourceCreated(
     return;
   }
 
+  if (nested_msg.type() == PpapiHostMsg_Graphics2D_Create::ID)
+    graphics_2d_set_.insert(params.pp_resource());
+
   resources_[params.pp_resource()] =
       linked_ptr<ResourceHost>(resource_host.release());
 }
 
-void PpapiHost::OnHostMsgResourceDestroyed(PP_Resource resource) {
-  ResourceMap::iterator found = resources_.find(resource);
-  if (found == resources_.end()) {
+// static
+template <typename Container, typename Element>
+void PpapiHost::ReleaseResource(Container container, Element element) {
+  typename Container::iterator found = container.find(element);
+  if (found == container.end()) {
     NOTREACHED();
     return;
   }
-  resources_.erase(found);
+  container.erase(found);
 }
 
-ResourceHost* PpapiHost::GetResourceHost(PP_Resource resource) {
-  ResourceMap::iterator found = resources_.find(resource);
+void PpapiHost::OnHostMsgResourceDestroyed(PP_Resource resource) {
+  ReleaseResource(resources_, resource);
+  ReleaseResource(graphics_2d_set_, resource);
+}
+
+ResourceHost* PpapiHost::GetResourceHost(PP_Resource resource) const {
+  ResourceMap::const_iterator found = resources_.find(resource);
   return found == resources_.end() ? NULL : found->second.get();
 }
 
+bool PpapiHost::IsGraphics2DResource(PP_Resource resource) const {
+  return graphics_2d_set_.find(resource) != graphics_2d_set_.end();
+}
+
 }  // namespace host
 }  // namespace ppapi