Make the ENABLE_APP_LIST build flag work on Linux

ui/app_list/app_list_constants.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 "ui/app_list/app_list_constants.h"
 
 #include "build/build_config.h"
 #include "ui/gfx/color_palette.h"
 
 namespace app_list {
 
 const SkColor kContentsBackgroundColor = SkColorSetRGB(0xF2, 0xF2, 0xF2);
 const SkColor kSearchBoxBackground = SK_ColorWHITE;
 
 const SkColor kSearchTextColor = SkColorSetRGB(0x33, 0x33, 0x33);
 
 // In Windows, transparent background color will cause ugly text rendering,
 // therefore kContentsBackgroundColor should be used. See crbug.com/406989
 #if defined(OS_CHROMEOS)
 const SkColor kLabelBackgroundColor = SK_ColorTRANSPARENT;
 #else
 const SkColor kLabelBackgroundColor = kContentsBackgroundColor;
 #endif
 
 const SkColor kTopSeparatorColor = SkColorSetRGB(0xC0, 0xC0, 0xC0);
 const SkColor kBottomSeparatorColor = SkColorSetRGB(0xC0, 0xC0, 0xC0);
 
-// The color of the separator used inside dialogs in the app list.
-const SkColor kDialogSeparatorColor = SkColorSetRGB(0xD1, 0xD1, 0xD1);
-
 // The mouse hover colour (3% black).
 const SkColor kHighlightedColor = SkColorSetARGB(8, 0, 0, 0);
 // The keyboard select colour (6% black).
 const SkColor kSelectedColor = SkColorSetARGB(15, 0, 0, 0);
 
 const SkColor kPagerHoverColor = SkColorSetRGB(0xB4, 0xB4, 0xB4);
 const SkColor kPagerNormalColor = SkColorSetRGB(0xE2, 0xE2, 0xE2);
 const SkColor kPagerSelectedColor = SkColorSetRGB(0x46, 0x8F, 0xFC);
 
 const SkColor kResultBorderColor = SkColorSetRGB(0xE5, 0xE5, 0xE5);
@@ skipping 136 matching lines @@
 }
 
 const gfx::ShadowValues& IconEndShadows() {
   CR_DEFINE_STATIC_LOCAL(const gfx::ShadowValues, icon_shadows,
                          (1, gfx::ShadowValue(gfx::Vector2d(0, 4), 4,
                                               SkColorSetARGB(0x50, 0, 0, 0))));
   return icon_shadows;
 }
 
 }  // namespace app_list