Correct ENABLE_MEDIA_ROUTER defines to fix compilation without it.

chrome/browser/extensions/chrome_mojo_service_registration.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/chrome_mojo_service_registration.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "chrome/common/chrome_switches.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/service_registry.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/permissions/api_permission.h"
 #include "extensions/common/permissions/permissions_data.h"
 #include "extensions/common/switches.h"
 
 #if defined(ENABLE_MEDIA_ROUTER)
 #include "chrome/browser/media/router/media_router_mojo_impl.h"
 #endif
 
 namespace extensions {
 
 void RegisterChromeServicesForFrame(content::RenderFrameHost* render_frame_host,
                                     const Extension* extension) {
   DCHECK(render_frame_host);
   DCHECK(extension);
 
-  content::ServiceRegistry* service_registry =
-      render_frame_host->GetServiceRegistry();
-
 #if defined(ENABLE_MEDIA_ROUTER)
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           ::switches::kEnableMediaRouter)) {
     if (extension->permissions_data()->HasAPIPermission(
             APIPermission::kMediaRouterPrivate)) {
-      service_registry->AddService(base::Bind(
+      render_frame_host->GetServiceRegistry()->AddService(base::Bind(
           media_router::MediaRouterMojoImpl::BindToRequest, extension->id(),
           render_frame_host->GetProcess()->GetBrowserContext()));
     }
   }
 #endif  // defined(ENABLE_MEDIA_ROUTER)
 }
 
 }  // namespace extensions