ash uber tray: Update the volume icon for various levels of volumes.

ash/system/brightness/tray_brightness.cc

Index: ash/system/brightness/tray_brightness.cc
diff --git a/ash/system/brightness/tray_brightness.cc b/ash/system/brightness/tray_brightness.cc
index 3aeb53b2270c42af32913189cad274a61466ab87..655c373be8bb2bbd0f7e5cd962ee00afb0a4c8f0 100644
--- a/ash/system/brightness/tray_brightness.cc
+++ b/ash/system/brightness/tray_brightness.cc
@@ -20,6 +20,9 @@
 #include "ui/views/controls/image_view.h"
 #include "ui/views/view.h"
 
+namespace ash {
+namespace internal {
+
 namespace tray {
 
 class BrightnessView : public views::View,
@@ -76,9 +79,6 @@ class BrightnessView : public views::View,
 
 }  // namespace tray
 
-namespace ash {
-namespace internal {
-
 TrayBrightness::TrayBrightness() {}
 
 TrayBrightness::~TrayBrightness() {}