Provide the DeviceManager service to the renderer directly, no app.

content/public/browser/content_browser_client.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_
 #define CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 604 matching lines @@
   // Allows to register browser Mojo services exposed through the
   // RenderProcessHost.
   virtual void RegisterRenderProcessMojoServices(ServiceRegistry* registry) {}
 
   // Allows to register browser Mojo services exposed through the
   // FrameMojoShell.
   virtual void RegisterFrameMojoShellServices(
       ServiceRegistry* registry,
       RenderFrameHost* render_frame_host) {}
 
+  // Allows to register browser Mojo services exposed through the
+  // RenderFrameHost.
+  virtual void RegisterRenderFrameMojoServices(
+      ServiceRegistry* registry,
+      RenderFrameHost* render_frame_host) {}
+
   using StaticMojoApplicationMap =
       std::map<GURL, base::Callback<scoped_ptr<mojo::ApplicationDelegate>()>>;
 
   // Registers Mojo applications to be loaded in the browser process by the
   // browser's global Mojo shell.
   virtual void RegisterInProcessMojoApplications(
       StaticMojoApplicationMap* apps) {}
 
   using OutOfProcessMojoApplicationMap = std::map<GURL, base::string16>;
 
@@ skipping 75 matching lines @@
   // Allows an embedder to provide its own ExternalVideoSurfaceContainer
   // implementation.  Return nullptr to disable external surface video.
   virtual ExternalVideoSurfaceContainer*
   OverrideCreateExternalVideoSurfaceContainer(WebContents* web_contents);
 #endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_