Update references to Blink's Platform API headers

chrome/renderer/extensions/dom_activity_logger.cc

 // Copyright (c) 2013 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/renderer/extensions/dom_activity_logger.h"
 
 #include "base/logging.h"
 #include "chrome/common/extensions/extension_messages.h"
 #include "chrome/renderer/chrome_render_process_observer.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/v8_value_converter.h"
-#include "third_party/WebKit/Source/Platform/chromium/public/WebString.h"
+#include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDOMActivityLogger.h"
 #include "v8/include/v8.h"
 
 using content::V8ValueConverter;
 
 namespace extensions {
 
 DOMActivityLogger::DOMActivityLogger(const std::string& extension_id,
                                      const GURL& url,
                                      const string16& title)
@@ skipping 32 matching lines @@
   // If there is no logger registered for world_id, construct a new logger
   // and register it with world_id.
   if (!WebKit::hasDOMActivityLogger(world_id)) {
     DOMActivityLogger* logger = new DOMActivityLogger(extension_id, url, title);
     WebKit::setDOMActivityLogger(world_id, logger);
   }
 }
 
 }  // namespace extensions