Port more String and HashMap usages

services/sky/dart_library_provider_impl.h

Index: services/sky/dart_library_provider_impl.h
diff --git a/services/sky/dart_library_provider_impl.h b/services/sky/dart_library_provider_impl.h
index eea151089a993640056b8eb7e7050c796958e016..d66564a69408cd1207462b50db8241d7a8683de9 100644
--- a/services/sky/dart_library_provider_impl.h
+++ b/services/sky/dart_library_provider_impl.h
@@ -16,7 +16,7 @@ class DartLibraryProviderImpl : public shell::DartLibraryProviderNetwork {
     PrefetchedLibrary();
     ~PrefetchedLibrary();
 
-    String name;
+    std::string name;
     mojo::ScopedDataPipeConsumerHandle pipe;
   };
 
@@ -25,7 +25,7 @@ class DartLibraryProviderImpl : public shell::DartLibraryProviderNetwork {
   ~DartLibraryProviderImpl() override;
 
  private:
-  void GetLibraryAsStream(const String& name,
+  void GetLibraryAsStream(const std::string& name,
                           blink::DataPipeConsumerCallback callback) override;
 
   scoped_ptr<PrefetchedLibrary> prefetched_library_;