Move upgrade severity colors into NativeTheme.

chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc

 // Copyright (c) 2013 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 "chrome/browser/ui/libgtk2ui/native_theme_gtk2.h"
 
 #include <gtk/gtk.h>
 
 #include "chrome/browser/ui/libgtk2ui/chrome_gtk_frame.h"
 #include "chrome/browser/ui/libgtk2ui/chrome_gtk_menu_subclasses.h"
@@ skipping 436 matching lines @@
     case kColorId_ThrobberSpinningColor:
     case kColorId_ThrobberLightColor:
       return GetSystemColor(kColorId_TextfieldSelectionBackgroundFocused);
 
     case kColorId_ThrobberWaitingColor:
       return color_utils::AlphaBlend(
           GetSystemColor(kColorId_TextfieldSelectionBackgroundFocused),
           GetBGColor(GetWindow(), NORMAL),
           0x80);
 
+    // Alert icons
+    // These aren't yet used in any GTK NativeTheme context, so they don't have
+    // definitions.
+    case kColorId_AlertSeverityLow:
+    case kColorId_AlertSeverityMedium:
+    case kColorId_AlertSeverityHigh:
     case kColorId_NumColors:
       NOTREACHED();
       break;
   }
 
   return kInvalidColorIdColor;
 }
 
 // Get ChromeGtkFrame theme colors. No-op in GTK3.
 bool NativeThemeGtk2::GetChromeStyleColor(const char* style_property,
@@ skipping 101 matching lines @@
 
   if (!fake_menu_item) {
     fake_menu_item = gtk_custom_menu_item_new();
     gtk_menu_shell_append(GTK_MENU_SHELL(GetMenu()), fake_menu_item);
   }
 
   return fake_menu_item;
 }
 
 }  // namespace libgtk2ui