Port more String and HashMap usages

services/sky/dart_library_provider_impl.h

 // Copyright 2015 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 SERVICES_SKY_DART_LIBRARY_PROVIDER_IMPL_H_
 #define SERVICES_SKY_DART_LIBRARY_PROVIDER_IMPL_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "sky/shell/dart/dart_library_provider_network.h"
 
 namespace sky {
 
 class DartLibraryProviderImpl : public shell::DartLibraryProviderNetwork {
  public:
   struct PrefetchedLibrary {
     PrefetchedLibrary();
     ~PrefetchedLibrary();
 
-    String name;
+    std::string name;
     mojo::ScopedDataPipeConsumerHandle pipe;
   };
 
   explicit DartLibraryProviderImpl(mojo::NetworkService* network_service,
                                    scoped_ptr<PrefetchedLibrary> prefetched);
   ~DartLibraryProviderImpl() override;
 
  private:
-  void GetLibraryAsStream(const String& name,
+  void GetLibraryAsStream(const std::string& name,
                           blink::DataPipeConsumerCallback callback) override;
 
   scoped_ptr<PrefetchedLibrary> prefetched_library_;
 
   DISALLOW_COPY_AND_ASSIGN(DartLibraryProviderImpl);
 };
 
 }  // namespace sky
 
 #endif  // SERVICES_SKY_DART_LIBRARY_PROVIDER_IMPL_H_