Move gtk_settings_get_default() call to the UI thread.

chrome/browser/icon_loader.cc

 // Copyright (c) 2009 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/message_loop.h"
+#include "base/mime_util.h"
 #include "base/thread.h"
 #include "chrome/browser/browser_process.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 IconLoader::IconLoader(const IconGroupID& group, IconSize size,
                        Delegate* delegate)
     : group_(group),
       icon_size_(size),
       bitmap_(NULL),
       delegate_(delegate) {
 }
 
 IconLoader::~IconLoader() {
   delete bitmap_;
 }
 
 void IconLoader::Start() {
   target_message_loop_ = MessageLoop::current();
 
+#if defined(OS_LINUX)
+  // This call must happen on the UI thread before we can start loading icons.
+  mime_util::DetectGtkTheme();
+#endif
+
   g_browser_process->file_thread()->message_loop()->PostTask(FROM_HERE,
       NewRunnableMethod(this, &IconLoader::ReadIcon));
 }
 
 void IconLoader::NotifyDelegate() {
   if (delegate_->OnBitmapLoaded(this, bitmap_))
     bitmap_ = NULL;
 }