Add service registration for Mojo services defined under chrome/

extensions/browser/extension_web_contents_observer.h

Index: extensions/browser/extension_web_contents_observer.h
diff --git a/extensions/browser/extension_web_contents_observer.h b/extensions/browser/extension_web_contents_observer.h
index cd485605cc7e1145d888e2cda63503832c36a449..849851f4de4b32d2d26e326dbcaa568b85b775ad 100644
--- a/extensions/browser/extension_web_contents_observer.h
+++ b/extensions/browser/extension_web_contents_observer.h
@@ -53,6 +53,11 @@ class ExtensionWebContentsObserver : public content::WebContentsObserver {
   // the empty string if the render view host is not for a valid extension.
   static std::string GetExtensionId(content::RenderViewHost* render_view_host);
 
+  // Registers Mojo services with render_frame_host's ServiceRegistry.
+  // A subclass should invoke this method to register all Mojo services.
+  virtual void RegisterMojoServices(content::RenderFrameHost* render_frame_host,
+                                    const Extension* extension);
+
  private:
   // The BrowserContext associated with the WebContents being observed.
   content::BrowserContext* browser_context_;