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

ash/shell/shell_delegate_impl.cc

Index: ash/shell/shell_delegate_impl.cc
diff --git a/ash/shell/shell_delegate_impl.cc b/ash/shell/shell_delegate_impl.cc
index b9c7c018c1ac6c3c1dba4fa063a2fdc031ee9f99..5670f7d4e9b6995c03e59a5dd5f9857aeb3c199e 100644
--- a/ash/shell/shell_delegate_impl.cc
+++ b/ash/shell/shell_delegate_impl.cc
@@ -8,7 +8,6 @@
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/default_accessibility_delegate.h"
 #include "ash/common/gpu_support_stub.h"
-#include "ash/common/media_delegate.h"
 #include "ash/common/palette_delegate.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/system/tray/default_system_tray_delegate.h"
@@ -36,23 +35,6 @@ namespace ash {
 namespace shell {
 namespace {
 
-class MediaDelegateImpl : public MediaDelegate {
- public:
-  MediaDelegateImpl() {}
-  ~MediaDelegateImpl() override {}
-
-  // MediaDelegate:
-  void HandleMediaNextTrack() override {}
-  void HandleMediaPlayPause() override {}
-  void HandleMediaPrevTrack() override {}
-  MediaCaptureState GetMediaCaptureState(UserIndex index) override {
-    return MEDIA_CAPTURE_VIDEO;
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MediaDelegateImpl);
-};
-
 class PaletteDelegateImpl : public PaletteDelegate {
  public:
   PaletteDelegateImpl() {}
@@ -239,10 +221,6 @@ AccessibilityDelegate* ShellDelegateImpl::CreateAccessibilityDelegate() {
   return new DefaultAccessibilityDelegate;
 }
 
-MediaDelegate* ShellDelegateImpl::CreateMediaDelegate() {
-  return new MediaDelegateImpl;
-}
-
 std::unique_ptr<PaletteDelegate> ShellDelegateImpl::CreatePaletteDelegate() {
   return base::MakeUnique<PaletteDelegateImpl>();
 }