Add support for external out-of-process PPAPI plugins in the browser.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
===================================================================
--- content/public/browser/content_browser_client.h	(revision 166155)
+++ content/public/browser/content_browser_client.h	(working copy)
@@ -436,11 +436,15 @@
   // else we should do with the file.
   virtual std::string GetDefaultDownloadName();
 
-  // Notifification that a pepper plugin has just been spawned. This allows the
+  // Notification that a pepper plugin has just been spawned. This allows the
   // embedder to add filters onto the host to implement interfaces.
   // This is called on the IO thread.
   virtual void DidCreatePpapiPlugin(BrowserPpapiHost* browser_host) {}
 
+  // Gets the host for an external out-of-process plugin.
+  virtual content::BrowserPpapiHost* GetExternalBrowserPpapiHost(
+      int plugin_child_id);
+
   // Returns true if renderer processes can use Pepper TCP/UDP sockets from
   // the given origin and connection type.
   virtual bool AllowPepperSocketAPI(BrowserContext* browser_context,