PPAPI: Purposely leak ProxyLock, fix shutdown race

ppapi/proxy/plugin_globals.h

Index: ppapi/proxy/plugin_globals.h
diff --git a/ppapi/proxy/plugin_globals.h b/ppapi/proxy/plugin_globals.h
index 044cac7e25c049ea5df01d03ded33a6a0e3b7941..31adef558412d4c93c063d1363609f61f9703422 100644
--- a/ppapi/proxy/plugin_globals.h
+++ b/ppapi/proxy/plugin_globals.h
@@ -9,7 +9,6 @@
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/synchronization/lock.h"
 #include "base/threading/thread_local_storage.h"
 #include "ppapi/proxy/connection.h"
 #include "ppapi/proxy/plugin_resource_tracker.h"
@@ -64,7 +63,6 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   virtual PP_Module GetModuleForInstance(PP_Instance instance) OVERRIDE;
   virtual std::string GetCmdLine() OVERRIDE;
   virtual void PreCacheFontForFlash(const void* logfontw) OVERRIDE;
-  virtual base::Lock* GetProxyLock() OVERRIDE;
   virtual void LogWithSource(PP_Instance instance,
                              PP_LogLevel level,
                              const std::string& source,
@@ -143,8 +141,6 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   PluginVarTracker plugin_var_tracker_;
   scoped_refptr<CallbackTracker> callback_tracker_;
 
-  base::Lock proxy_lock_;
-
   scoped_ptr<base::ThreadLocalStorage::Slot> msg_loop_slot_;
   // Note that loop_for_main_thread's constructor sets msg_loop_slot_, so it
   // must be initialized after msg_loop_slot_ (hence the order here).