Add an interface for Flash to clear its data.

content/ppapi_plugin/ppapi_thread.h

Index: content/ppapi_plugin/ppapi_thread.h
diff --git a/content/ppapi_plugin/ppapi_thread.h b/content/ppapi_plugin/ppapi_thread.h
index 0784dd3349f41009ea86e518fdc94b28ea5cd1a2..894504653ca147d4f7b0ad16bf7129d3b07a8e80 100644
--- a/content/ppapi_plugin/ppapi_thread.h
+++ b/content/ppapi_plugin/ppapi_thread.h
@@ -55,9 +55,17 @@ class PpapiThread : public ChildThread,
   void OnMsgLoadPlugin(const FilePath& path);
   void OnMsgCreateChannel(base::ProcessHandle host_process_handle,
                           int renderer_id);
+  void OnMsgClearSiteData(const std::string& site,
+                          uint64 flags,
+                          uint64 max_age);
   void OnMsgSetNetworkState(bool online);
   void OnPluginDispatcherMessageReceived(const IPC::Message& msg);
 
+  // Requests that the plugin clear data, returning true on success.
+  bool ClearSiteData(const std::string& site,
+                     uint64 flags,
+                     uint64 max_age);
+
   // Sets up the channel to the given renderer. On success, returns true and
   // fills the given ChannelHandle with the information from the new channel.
   bool SetupRendererChannel(base::ProcessHandle host_process_handle,