Eliminate ash::internal namespace

ash/system/tray/tray_bar_button_with_title.h

Index: ash/system/tray/tray_bar_button_with_title.h
diff --git a/ash/system/tray/tray_bar_button_with_title.h b/ash/system/tray/tray_bar_button_with_title.h
index 8b63d4f8fa7434512d4dd4165997d03ba1c1ccdf..626a14a6942dced7ec7b388d8729a629f9dd5129 100644
--- a/ash/system/tray/tray_bar_button_with_title.h
+++ b/ash/system/tray/tray_bar_button_with_title.h
@@ -14,7 +14,6 @@ class Label;
 }
 
 namespace ash {
-namespace internal {
 
 // A button with a bar image and title text below the bar image. These buttons
 // will be used in audio and brightness control UI, which can be toggled with
@@ -43,7 +42,6 @@ class TrayBarButtonWithTitle : public views::CustomButton {
   DISALLOW_COPY_AND_ASSIGN(TrayBarButtonWithTitle);
 };
 
-}  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_TRAY_BAR_BUTTON_WITH_TITLE_H_