aura: Make the Linux version of IconLoader not require GTK+.

chrome/browser/icon_loader.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 "chrome/browser/icon_loader.h"
 
 #include "base/basictypes.h"
 #include "content/public/browser/browser_thread.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
-#if defined(TOOLKIT_GTK)
+#if defined(TOOLKIT_USES_GTK)
 #include "base/mime_util.h"
 #endif
 
 using content::BrowserThread;
 
 IconLoader::IconLoader(const IconGroupID& group, IconSize size,
                        Delegate* delegate)
     : target_message_loop_(NULL),
       group_(group),
       icon_size_(size),
       image_(NULL),
       delegate_(delegate) {
 }
 
 IconLoader::~IconLoader() {
 }
 
 void IconLoader::Start() {
   target_message_loop_ = base::MessageLoopProxy::current();
 
-#if defined(TOOLKIT_GTK)
+#if defined(TOOLKIT_USES_GTK)
   // This call must happen on the UI thread before we can start loading icons.
   mime_util::DetectGtkTheme();
 #endif
 
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(this, &IconLoader::ReadIcon));
 }
 
 void IconLoader::NotifyDelegate() {
   // If the delegate takes ownership of the Image, release it from the scoped
   // pointer.
   if (delegate_->OnImageLoaded(this, image_.get()))
     ignore_result(image_.release());  // Can't ignore return value.
 }