mash: Change the MediaDelegate to a Media{Controller,Client}.

ash/common/mojo_interface_factory.cc

Index: ash/common/mojo_interface_factory.cc
diff --git a/ash/common/mojo_interface_factory.cc b/ash/common/mojo_interface_factory.cc
index 3cdd6f1e764f48eed2846f6b20e4f75e378c132f..8a800134b220bde462cba05b87f077420c4d5a77 100644
--- a/ash/common/mojo_interface_factory.cc
+++ b/ash/common/mojo_interface_factory.cc
@@ -8,6 +8,7 @@
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/cast_config_controller.h"
+#include "ash/common/media_controller.h"
 #include "ash/common/new_window_controller.h"
 #include "ash/common/session/session_controller.h"
 #include "ash/common/shelf/shelf_controller.h"
@@ -43,6 +44,11 @@ void BindLocaleNotificationControllerOnMainThread(
       std::move(request));
 }
 
+void BindMediaControllerRequestOnMainThread(
+    mojom::MediaControllerRequest request) {
+  WmShell::Get()->media_controller()->BindRequest(std::move(request));
+}
+
 void BindNewWindowControllerRequestOnMainThread(
     mojom::NewWindowControllerRequest request) {
   WmShell::Get()->new_window_controller()->BindRequest(std::move(request));
@@ -96,6 +102,8 @@ void RegisterInterfaces(
   registry->AddInterface(
       base::Bind(&BindLocaleNotificationControllerOnMainThread),
       main_thread_task_runner);
+  registry->AddInterface(base::Bind(&BindMediaControllerRequestOnMainThread),
+                         main_thread_task_runner);
   registry->AddInterface(
       base::Bind(&BindNewWindowControllerRequestOnMainThread),
       main_thread_task_runner);