Fix the ref-count issue related to the url_loader parameter of PPP_Instance.HandleDocumentLoad().

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/6835002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@81618 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 24 insertions, 0 deletions

diff --git a/ppapi/proxy/ppp_instance_proxy.cc b/ppapi/proxy/ppp_instance_proxy.cc
index 393f031..98e2615 100644
--- a/ppapi/proxy/ppp_instance_proxy.cc
+++ b/ppapi/proxy/ppp_instance_proxy.cc
@@ -7,9 +7,11 @@
 #include <algorithm>
 
 #include "ppapi/c/pp_var.h"
+#include "ppapi/c/ppb_core.h"
 #include "ppapi/c/ppp_instance.h"
 #include "ppapi/proxy/host_dispatcher.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
+#include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppb_url_loader_proxy.h"
 
@@ -81,6 +83,20 @@ PP_Bool HandleDocumentLoad(PP_Instance instance,
       dispatcher->GetOrCreatePPBInterfaceProxy(INTERFACE_ID_PPB_URL_LOADER));
   url_loader_proxy->PrepareURLLoaderForSendingToPlugin(url_loader);
 
+  // PluginResourceTracker in the plugin process assumes that resources that it
+  // tracks have been addrefed on behalf of the plugin at the renderer side. So
+  // we explicitly do it for |url_loader| here.
+  //
+  // Please also see comments in PPP_Instance_Proxy::OnMsgHandleDocumentLoad()
+  // about releasing of this extra reference.
+  const PPB_Core* core = reinterpret_cast<const PPB_Core*>(
+      dispatcher->GetLocalInterface(PPB_CORE_INTERFACE));
+  if (!core) {
+    NOTREACHED();
+    return PP_FALSE;
+  }
+  core->AddRefResource(url_loader);
+
   HostResource serialized_loader;
   serialized_loader.SetHostResource(instance, url_loader);
   dispatcher->Send(new PpapiMsg_PPPInstance_HandleDocumentLoad(
@@ -224,6 +240,14 @@ void PPP_Instance_Proxy::OnMsgHandleDocumentLoad(PP_Instance instance,
       PPB_URLLoader_Proxy::TrackPluginResource(url_loader);
   *result = ppp_instance_target()->HandleDocumentLoad(
       instance, plugin_loader);
+
+  // This balances the one reference that TrackPluginResource() initialized it
+  // with. The plugin will normally take an additional reference which will keep
+  // the resource alive in the plugin (and the one reference in the renderer
+  // representing all plugin references).
+  // Once all references at the plugin side are released, the renderer side will
+  // be notified and release the reference added in HandleDocumentLoad() above.
+  PluginResourceTracker::GetInstance()->ReleaseResource(plugin_loader);
 }
 
 void PPP_Instance_Proxy::OnMsgGetInstanceObject(