Fix reentrancy in HandleInputEvent by posting a task

ppapi/proxy/ppp_instance_proxy.cc

Index: ppapi/proxy/ppp_instance_proxy.cc
diff --git a/ppapi/proxy/ppp_instance_proxy.cc b/ppapi/proxy/ppp_instance_proxy.cc
index b2103a3a4eea38a4699e9c8a0da020ea6dcea221..4d5bb3dd4f6cdaba9ef3cf225dad51c82aa1f97a 100644
--- a/ppapi/proxy/ppp_instance_proxy.cc
+++ b/ppapi/proxy/ppp_instance_proxy.cc
@@ -57,9 +57,12 @@ void DidChangeFocus(PP_Instance instance, PP_Bool has_focus) {
 PP_Bool HandleInputEvent(PP_Instance instance,
                          const PP_InputEvent* event) {
   PP_Bool result = PP_FALSE;
-  HostDispatcher::GetForInstance(instance)->Send(
-      new PpapiMsg_PPPInstance_HandleInputEvent(INTERFACE_ID_PPP_INSTANCE,
-                                                instance, *event, &result));
+  IPC::Message* msg = new PpapiMsg_PPPInstance_HandleInputEvent(
+      INTERFACE_ID_PPP_INSTANCE, instance, *event, &result);
+  // Make this message not unblock, to avoid re-entrancy problems when the
+  // plugin does a sync call to the renderer.

[brettw, 2011/02/02 05:00:08]

Can you add something like: "This will force any synchronous calls from the
plugin to complete before processing this message. We avoid deadlock by never
"setting unblock" on messages from the plugin to the renderer."

+  msg->set_unblock(false);
+  HostDispatcher::GetForInstance(instance)->Send(msg);
   return result;
 }