Change other usages of .size() to .empty() when applicable.

chrome/renderer/webworker_base.h

 // 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.
 
 #ifndef CHROME_RENDERER_WEBWORKER_BASE_H_
 #define CHROME_RENDERER_WEBWORKER_BASE_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 35 matching lines @@
   bool IsStarted();
 
   // Disconnects the worker (stops listening for incoming messages).
   void Disconnect();
 
   // Sends a message to the worker thread (forwarded via the RenderViewHost).
   // If WorkerStarted() has not yet been called, message is queued.
   bool Send(IPC::Message*);
 
   // Returns true if there are queued messages.
-  bool HasQueuedMessages() { return queued_messages_.size() != 0; }
+  bool HasQueuedMessages() { return !queued_messages_.empty(); }
 
   // Sends any messages currently in the queue.
   void SendQueuedMessages();
 
  protected:
   WebWorkerBase(ChildThread* child_thread,
                 unsigned long long document_id,
                 int route_id,
                 int render_view_route_id,
                 int parent_appcache_host_id);
@@ skipping 23 matching lines @@
   unsigned long long document_id_;
 
   // ID of our parent's appcache host, only valid for dedicated workers.
   int parent_appcache_host_id_;
 
   // Stores messages that were sent before the StartWorkerContext message.
   std::vector<IPC::Message*> queued_messages_;
 };
 
 #endif  // CHROME_RENDERER_WEBWORKER_BASE_H_