Remove duplicated headers

Source/web/tests/URLTestHelpers.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "URLTestHelpers.h"
 
 #include "public/platform/Platform.h"
-#include "public/platform/WebString.h"
 #include "public/platform/WebURL.h"
 #include "public/platform/WebURLResponse.h"
 #include "public/platform/WebUnitTestSupport.h"
 
 namespace blink {
 namespace URLTestHelpers {
 
 void registerMockedURLFromBaseURL(const WebString& baseURL, const WebString& fileName, const WebString& mimeType)
 {
     // fullURL = baseURL + fileName.
@@ skipping 17 matching lines @@
     std::string filePath = std::string(Platform::current()->unitTestSupport()->webKitRootDir().utf8().data());
     filePath.append("/Source/web/tests/data/");
     filePath.append(std::string(relativeBaseDirectory.utf8().data()));
     filePath.append(std::string(fileName.utf8().data()));
 
     Platform::current()->unitTestSupport()->registerMockedURL(fullURL, response, WebString::fromUTF8(filePath.c_str()));
 }
 
 } // namespace URLTestHelpers
 } // namespace blink