media: Generalize MediaPermissionDispatcher.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 59b2ed02d20416bde3d88627d90eef73d42b1ae8..c750abbbee6e5b9a70e170849d622ae9ebaa97dc 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -750,7 +750,6 @@ RenderFrameImpl::RenderFrameImpl(const CreateParams& params)
       handling_select_range_(false),
       notification_permission_dispatcher_(NULL),
       web_user_media_client_(NULL),
-      media_permission_dispatcher_(NULL),
       midi_dispatcher_(NULL),
 #if defined(OS_ANDROID)
       media_player_manager_(NULL),
@@ -5263,9 +5262,12 @@ RendererMediaPlayerManager* RenderFrameImpl::GetMediaPlayerManager() {
 #endif  // defined(OS_ANDROID)
 
 media::MediaPermission* RenderFrameImpl::GetMediaPermission() {
-  if (!media_permission_dispatcher_)
-    media_permission_dispatcher_ = new MediaPermissionDispatcher(this);
-  return media_permission_dispatcher_;
+  if (!media_permission_dispatcher_) {
+    media_permission_dispatcher_.reset(new MediaPermissionDispatcher(
+        base::Bind(&RenderFrameImpl::ConnectToService<PermissionService>,
+                   base::Unretained(this))));

[nasko, 2015/11/25 15:04:27]

Please add a comment why using base::Unretained(this) is safe.

+  }
+  return media_permission_dispatcher_.get();
 }
 
 #if defined(ENABLE_MOJO_MEDIA)
@@ -5334,17 +5336,23 @@ void RenderFrameImpl::RegisterMojoServices() {
   }
 }
 
+template <typename Interface>
+void RenderFrameImpl::ConnectToService(
+    mojo::InterfaceRequest<Interface> request) {
+  GetServiceRegistry()->ConnectToRemoteService(std::move(request));
+}
+
 mojo::ServiceProviderPtr RenderFrameImpl::ConnectToApplication(
     const GURL& url) {
   if (!mojo_shell_)
-    GetServiceRegistry()->ConnectToRemoteService(mojo::GetProxy(&mojo_shell_));
+    ConnectToService(mojo::GetProxy(&mojo_shell_));
   mojo::ServiceProviderPtr service_provider;
   mojo::URLRequestPtr request(mojo::URLRequest::New());
   request->url = mojo::String::From(url);
   mojo_shell_->ConnectToApplication(request.Pass(), GetProxy(&service_provider),
                                     nullptr, nullptr,
                                     base::Bind(&OnGotContentHandlerID));
-  return service_provider.Pass();
+  return std::move(service_provider);
 }
 
 media::RendererWebMediaPlayerDelegate*