When clearing plugin data at shutdown, wait for it to finish.

chrome/browser/plugin_process_host.h

Index: chrome/browser/plugin_process_host.h
diff --git a/chrome/browser/plugin_process_host.h b/chrome/browser/plugin_process_host.h
index d30a77aaf1dce6e4f73a4221bbf016cdb0fae1bb..0fefbb706b3a844f190d618d161ff4530c602e54 100644
--- a/chrome/browser/plugin_process_host.h
+++ b/chrome/browser/plugin_process_host.h
@@ -48,6 +48,8 @@ class PluginProcessHost : public BrowserChildProcessHost,
     virtual int ID() = 0;
     virtual bool OffTheRecord() = 0;
     virtual void SetPluginInfo(const webkit::npapi::WebPluginInfo& info) = 0;
+    // Called when we we have found the plugin process.
+    virtual void OnPluginProcessFound(PluginProcessHost* host) { }
     // The client should delete itself when one of these methods is called.
     virtual void OnChannelOpened(const IPC::ChannelHandle& handle) = 0;
     virtual void OnError() = 0;
@@ -61,7 +63,8 @@ class PluginProcessHost : public BrowserChildProcessHost,
 
   // Initialize the new plugin process, returning true on success. This must
   // be called before the object can be used.
-  bool Init(const webkit::npapi::WebPluginInfo& info, const std::string& locale);
+  bool Init(const webkit::npapi::WebPluginInfo& info,
+            const std::string& locale);
 
   // Force the plugin process to shutdown (cleanly).
   virtual void ForceShutdown();