Mojo C++ bindings: switch services/navigation mojom target to use STL types.

mash/webtest/webtest.cc

 // 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.
 
 #include "mash/webtest/webtest.h"
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string16.h"
@@ skipping 85 matching lines @@
       ui::mojom::WindowTreeClientPtr client;
       view_->GetWindowTreeClient(GetProxy(&client));
       content_area_->Embed(std::move(client));
     }
   }
 
   // navigation::mojom::ViewClient:
   void OpenURL(navigation::mojom::OpenURLParamsPtr params) override {}
   void LoadingStateChanged(bool is_loading) override {}
   void NavigationStateChanged(const GURL& url,
-                              const mojo::String& title,
+                              const std::string& title,
                               bool can_go_back,
                               bool can_go_forward) override {
-    current_title_ = base::UTF8ToUTF16(title.get());
+    current_title_ = base::UTF8ToUTF16(title);
     GetWidget()->UpdateWindowTitle();
   }
   void LoadProgressChanged(double progress) override {}
   void UpdateHoverURL(const GURL& url) override {}
   void ViewCreated(navigation::mojom::ViewPtr view,
                    navigation::mojom::ViewClientRequest request,
                    bool is_popup,
                    const gfx::Rect& initial_rect,
                    bool user_gesture) override {
     views::Widget* window = views::Widget::CreateWindowWithContextAndBounds(
@@ skipping 77 matching lines @@
   AddWindow(window);
 }
 
 void Webtest::Create(const service_manager::Identity& remote_identity,
                      mojom::LaunchableRequest request) {
   bindings_.AddBinding(this, std::move(request));
 }
 
 }  // namespace webtest
 }  // namespace mash