Make gpu black list work again on Linux

content/public/browser/browser_thread.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_
 #define CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 179 matching lines @@
   // prior to browser shutdown.
   // Note: see related ContentBrowserClient::PostAfterStartupTask.
   static void PostAfterStartupTask(
       const tracked_objects::Location& from_here,
       const scoped_refptr<base::TaskRunner>& task_runner,
       const base::Closure& task);
 
   // Returns the thread pool used for blocking file I/O. Use this object to
   // perform random blocking operations such as file writes or querying the
   // Windows registry.
-  static base::SequencedWorkerPool* GetBlockingPool() WARN_UNUSED_RESULT;
+  static base::SequencedWorkerPool* GetBlockingPool();
 
   // Callable on any thread.  Returns whether the given well-known thread is
   // initialized.
   static bool IsThreadInitialized(ID identifier) WARN_UNUSED_RESULT;
 
   // Callable on any thread.  Returns whether you're currently on a particular
   // thread.  To DCHECK this, use the DCHECK_CURRENTLY_ON() macro above.
   static bool CurrentlyOn(ID identifier) WARN_UNUSED_RESULT;
 
   // Callable on any thread.  Returns whether the threads message loop is valid.
@@ skipping 86 matching lines @@
  private:
   friend class BrowserThreadImpl;
 
   BrowserThread() {}
   DISALLOW_COPY_AND_ASSIGN(BrowserThread);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_