Build fix for win_aura

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/8343040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@107661 0039d316-1c4b-4281-b951-d872f2087c98

ui/aura/aura.gyp

@@ -23,6 +23,7 @@
         'AURA_IMPLEMENTATION',
       ],
       'sources': [
+        'aura_constants.cc',
         'aura_constants.h',
         'aura_switches.cc',
         'aura_switches.h',

ui/aura/aura_constants.cc

+// Copyright (c) 2011 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/aura/aura_constants.h"
+
+namespace aura {
+
+const char* kTooltipTextKey = "TooltipTextKey";
+
+}

ui/aura/aura_constants.h

@@ -10,7 +10,7 @@
 
 namespace aura {
 
-AURA_EXPORT const char* kTooltipTextKey = "TooltipTextKey";
+AURA_EXPORT extern const char* kTooltipTextKey;
 
 }  // namespace aura