Enable the volume slider in Ash for windows.

ash/system/tray/system_tray.cc

 // 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.
 
 #include "ash/system/tray/system_tray.h"
 
 #include "ash/ash_switches.h"
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shell.h"
@@ skipping 44 matching lines @@
 #include "ash/system/chromeos/network/tray_network.h"
 #include "ash/system/chromeos/network/tray_sms.h"
 #include "ash/system/chromeos/network/tray_vpn.h"
 #include "ash/system/chromeos/power/tray_power.h"
 #include "ash/system/chromeos/screen_security/screen_capture_tray_item.h"
 #include "ash/system/chromeos/screen_security/screen_share_tray_item.h"
 #include "ash/system/chromeos/settings/tray_settings.h"
 #include "ash/system/chromeos/tray_display.h"
 #include "ash/system/chromeos/tray_tracing.h"
 #include "ui/message_center/message_center.h"
+#elif defined(OS_WIN)
+#include "ash/system/win/audio/tray_audio_win.h"
+#include "media/audio/win/core_audio_util_win.h"
 #endif
 
 using views::TrayBubbleView;
 
 namespace ash {
 
 // The minimum width of the system tray menu width.
 const int kMinimumSystemTrayMenuWidth = 300;
 
 namespace internal {
@@ skipping 122 matching lines @@
   AddTrayItem(new internal::ScreenCaptureTrayItem(this));
   AddTrayItem(new internal::ScreenShareTrayItem(this));
   AddTrayItem(new internal::TrayAudioChromeOs(this));
   AddTrayItem(new internal::TrayBrightness(this));
   AddTrayItem(new internal::TrayCapsLock(this));
   AddTrayItem(new internal::TraySettings(this));
   AddTrayItem(new internal::TrayUpdate(this));
   AddTrayItem(tray_date_);
 #elif defined(OS_WIN)
   AddTrayItem(tray_accessibility_);
+  if (media::CoreAudioUtil::IsSupported())

[henrika (OOO until Aug 14), 2014/02/26 09:10:05]

Just checking. What happens on Windows XP here?

[zturner, 2014/02/26 17:50:29]

"Windows Ash" is mostly synonymous with "Chrome Windows 8 mode".  So as the name
implies, you cannot run Ash on any version of Windows prior to 8 (actually you
can make it work on Win7, but it's not a supported configuration, and may be
broken).

+    AddTrayItem(new internal::TrayAudioWin(this));
   AddTrayItem(new internal::TrayUpdate(this));
   AddTrayItem(tray_date_);
 #elif defined(OS_LINUX)
   AddTrayItem(new internal::TrayIME(this));
   AddTrayItem(tray_accessibility_);
   AddTrayItem(new internal::TrayBluetooth(this));
   AddTrayItem(new internal::TrayDrive(this));
   AddTrayItem(new internal::TrayCapsLock(this));
   AddTrayItem(new internal::TrayUpdate(this));
   AddTrayItem(tray_date_);
@@ skipping 511 matching lines @@
   system_bubble_.reset();
   // When closing a system bubble with the alternate shelf layout, we need to
   // turn off the active tinting of the shelf.
   if (full_system_tray_menu_) {
     SetDrawBackgroundAsActive(false);
     full_system_tray_menu_ = false;
   }
 }
 
 }  // namespace ash