Refactor: Simplify WaitableEventWatcher.

content/browser/plugin_service_impl.h

Index: content/browser/plugin_service_impl.h
diff --git a/content/browser/plugin_service_impl.h b/content/browser/plugin_service_impl.h
index 8808c4b433802686c6954d17ceee5e5c722e32d0..134cb43479bbdbb1887ade8548afd5e79c058e17 100644
--- a/content/browser/plugin_service_impl.h
+++ b/content/browser/plugin_service_impl.h
@@ -64,8 +64,7 @@ struct PluginServiceFilterParams {
 };
 
 class CONTENT_EXPORT PluginServiceImpl
-    : NON_EXPORTED_BASE(public PluginService),
-      public base::WaitableEventWatcher::Delegate {
+    : NON_EXPORTED_BASE(public PluginService) {
  public:
   // Returns the PluginServiceImpl singleton.
   static PluginServiceImpl* GetInstance();
@@ -157,9 +156,7 @@ class CONTENT_EXPORT PluginServiceImpl
   PluginServiceImpl();
   virtual ~PluginServiceImpl();
 
-  // base::WaitableEventWatcher::Delegate implementation.
-  virtual void OnWaitableEventSignaled(
-      base::WaitableEvent* waitable_event) OVERRIDE;
+  void OnWaitableEventSignaled(base::WaitableEvent* waitable_event);
 
   // Returns the plugin process host corresponding to the plugin process that
   // has been started by this service. Returns NULL if no process has been
@@ -216,6 +213,7 @@ class CONTENT_EXPORT PluginServiceImpl
   scoped_ptr<base::WaitableEvent> hklm_event_;
   base::WaitableEventWatcher hkcu_watcher_;
   base::WaitableEventWatcher hklm_watcher_;
+  base::Callback<void(base::WaitableEvent*)> registry_watcher_callback_;
 #endif
 
 #if defined(OS_POSIX) && !defined(OS_OPENBSD) && !defined(OS_ANDROID)