Mojo C++ bindings: switch WebKit mojom targets to use STL/WTF types.

content/browser/hyphenation/hyphenation_impl.h

 // Copyright 2016 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_BROWSER_HYPHENATION_HYPHENATION_IMPL_H_
 #define CONTENT_BROWSER_HYPHENATION_HYPHENATION_IMPL_H_
 
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "third_party/WebKit/public/platform/modules/hyphenation/hyphenation.mojom.h"
 
 namespace hyphenation {
 
 class HyphenationImpl : public blink::mojom::Hyphenation {
  public:
   HyphenationImpl();
   ~HyphenationImpl() override;
 
   static void Create(blink::mojom::HyphenationRequest);
 
   // Hyphenation:
-  void OpenDictionary(const mojo::String& locale,
+  void OpenDictionary(const std::string& locale,
                       const OpenDictionaryCallback& callback) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(HyphenationImpl);
 };
 
 }  // namespace hyphenation
 
 #endif  // CONTENT_BROWSER_HYPHENATION_HYPHENATION_IMPL_H_