Use mojo volume interfaces for mash and classic ash.

chrome/browser/ui/ash/volume_controller_chromeos.cc

Index: chrome/browser/ui/ash/volume_controller_chromeos.cc
diff --git a/chrome/browser/ui/ash/volume_controller_chromeos.cc b/chrome/browser/ui/ash/volume_controller_chromeos.cc
index 68dd5928b4e39576e48953f9e9512a0b8257f21c..1a36427d9c0c198c876b3a9e591b0cc49f21b7bb 100644
--- a/chrome/browser/ui/ash/volume_controller_chromeos.cc
+++ b/chrome/browser/ui/ash/volume_controller_chromeos.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2016 The Chromium Authors. All rights reserved.

[James Cook, 2016/10/18 23:53:40]

nit: I don't think you need to update this.

[msw, 2016/10/19 15:24:10]

Done.

 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -52,17 +52,16 @@ VolumeController::~VolumeController() {
     CrasAudioHandler::Get()->RemoveAudioObserver(this);
 }
 
-void VolumeController::HandleVolumeMute(const ui::Accelerator& accelerator) {
-  if (accelerator.key_code() == ui::VKEY_VOLUME_MUTE)
-    content::RecordAction(base::UserMetricsAction("Accel_VolumeMute_F8"));
+void VolumeController::BindRequest(
+    ash::mojom::VolumeControllerRequest request) {
+  bindings_.AddBinding(this, std::move(request));
+}
 
+void VolumeController::VolumeMute() {
   CrasAudioHandler::Get()->SetOutputMute(true);
 }
 
-void VolumeController::HandleVolumeDown(const ui::Accelerator& accelerator) {
-  if (accelerator.key_code() == ui::VKEY_VOLUME_DOWN)
-    content::RecordAction(base::UserMetricsAction("Accel_VolumeDown_F9"));
-
+void VolumeController::VolumeDown() {
   CrasAudioHandler* audio_handler = CrasAudioHandler::Get();
   if (audio_handler->IsOutputMuted()) {
     audio_handler->SetOutputVolumePercent(0);
@@ -75,10 +74,7 @@ void VolumeController::HandleVolumeDown(const ui::Accelerator& accelerator) {
   }
 }
 
-void VolumeController::HandleVolumeUp(const ui::Accelerator& accelerator) {
-  if (accelerator.key_code() == ui::VKEY_VOLUME_UP)
-    content::RecordAction(base::UserMetricsAction("Accel_VolumeUp_F10"));
-
+void VolumeController::VolumeUp() {
   CrasAudioHandler* audio_handler = CrasAudioHandler::Get();
   bool play_sound = false;
   if (audio_handler->IsOutputMuted()) {