Mark some content::BrowserThread methods with WARN_UNUSED_RESULT.

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/basictypes.h"
@@ skipping 167 matching lines @@
       const base::Closure& task,
       const base::Closure& reply);
   static bool PostBlockingPoolSequencedTask(
       const std::string& sequence_token_name,
       const tracked_objects::Location& from_here,
       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();
+  static base::SequencedWorkerPool* GetBlockingPool() WARN_UNUSED_RESULT;
 
   // Callable on any thread.  Returns whether the given well-known thread is
   // initialized.
-  static bool IsThreadInitialized(ID identifier);
+  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);
+  static bool CurrentlyOn(ID identifier) WARN_UNUSED_RESULT;
 
   // Callable on any thread.  Returns whether the threads message loop is valid.
   // If this returns false it means the thread is in the process of shutting
   // down.
-  static bool IsMessageLoopValid(ID identifier);
+  static bool IsMessageLoopValid(ID identifier) WARN_UNUSED_RESULT;
 
   // If the current message loop is one of the known threads, returns true and
   // sets identifier to its ID.  Otherwise returns false.
-  static bool GetCurrentThreadIdentifier(ID* identifier);
+  static bool GetCurrentThreadIdentifier(ID* identifier) WARN_UNUSED_RESULT;
 
   // Callers can hold on to a refcounted MessageLoopProxy beyond the lifetime
   // of the thread.
   static scoped_refptr<base::MessageLoopProxy> GetMessageLoopProxyForThread(
       ID identifier);
 
   // Returns a pointer to the thread's message loop, which will become
   // invalid during shutdown, so you probably shouldn't hold onto it.
   //
   // This must not be called before the thread is started, or after
@@ skipping 60 matching lines @@
  private:
   friend class BrowserThreadImpl;
 
   BrowserThread() {}
   DISALLOW_COPY_AND_ASSIGN(BrowserThread);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_