linux: Both gtk and the aura port should set the icon theme name.

chrome/browser/icon_loader.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 "chrome/browser/icon_loader.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "content/public/browser/browser_thread.h"
 
-#if defined(TOOLKIT_GTK)
-#include "base/nix/mime_util_xdg.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)
-  // This call must happen on the UI thread before we can start loading icons.
-  base::nix::DetectGtkTheme();
-#endif
-
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
       base::Bind(&IconLoader::ReadIcon, this));
 }
 
 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.
 }