Refactor PPAPI proxy resource handling to maintain which host they came from,...

ppapi/proxy/ppp_instance_proxy.cc

Index: ppapi/proxy/ppp_instance_proxy.cc
===================================================================
--- ppapi/proxy/ppp_instance_proxy.cc	(revision 72517)
+++ ppapi/proxy/ppp_instance_proxy.cc	(working copy)
@@ -66,9 +66,11 @@
 PP_Bool HandleDocumentLoad(PP_Instance instance,
                            PP_Resource url_loader) {
   PP_Bool result = PP_FALSE;
+  SerializedResource serialized_loader;
+  serialized_loader.set_host_resource(url_loader);
   HostDispatcher::GetForInstance(instance)->Send(
       new PpapiMsg_PPPInstance_HandleDocumentLoad(INTERFACE_ID_PPP_INSTANCE,
-                                                  instance, url_loader,
+                                                  instance, serialized_loader,
                                                   &result));
   return result;
 }
@@ -180,11 +182,12 @@
 }
 
 void PPP_Instance_Proxy::OnMsgHandleDocumentLoad(PP_Instance instance,
-                                                 PP_Resource url_loader,
+                                                 SerializedResource url_loader,
                                                  PP_Bool* result) {
-  PPB_URLLoader_Proxy::TrackPluginResource(instance, url_loader);
+  PP_Resource plugin_loader =
+      PPB_URLLoader_Proxy::TrackPluginResource(instance, url_loader);
   *result = ppp_instance_target()->HandleDocumentLoad(
-      instance, url_loader);
+      instance, plugin_loader);
 }
 
 void PPP_Instance_Proxy::OnMsgGetInstanceObject(