Cleanup: IWYU for BrowserThread.

chrome/browser/web_applications/web_app_linux.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/web_applications/web_app.h"
 
 #include "base/environment.h"
+#include "base/logging.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace web_app {
 namespace internals {
 
 void CreateShortcutTask(const FilePath& web_app_path,
                         const FilePath& profile_path,
                         const ShellIntegration::ShortcutInfo& shortcut_info) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
 
   scoped_ptr<base::Environment> env(base::Environment::Create());
 
   std::string shortcut_template;
   if (!ShellIntegration::GetDesktopShortcutTemplate(env.get(),
                                                     &shortcut_template)) {
     return;
   }
   ShellIntegration::CreateDesktopShortcut(shortcut_info, shortcut_template);
 }
 
 }  // namespace internals
 }  // namespace web_app