diff --git a/engine/src/flutter/shell/dart/dart_library_provider_files.cc b/engine/src/flutter/shell/dart/dart_library_provider_files.cc
index 4c0e267ae0e..2bed8e8e9e3 100644
--- a/engine/src/flutter/shell/dart/dart_library_provider_files.cc
+++ b/engine/src/flutter/shell/dart/dart_library_provider_files.cc
@@ -50,12 +50,12 @@ DartLibraryProviderFiles::~DartLibraryProviderFiles() {
 }
 
 void DartLibraryProviderFiles::GetLibraryAsStream(
-    const String& name,
+    const std::string& name,
     blink::DataPipeConsumerCallback callback) {
   mojo::DataPipe pipe;
   callback.Run(pipe.consumer_handle.Pass());
 
-  base::FilePath source(name.toUTF8());
+  base::FilePath source(name);
   scoped_refptr<base::TaskRunner> runner =
       base::WorkerPool::GetTaskRunner(true);
   mojo::common::CopyFromFile(source, pipe.producer_handle.Pass(), 0,
diff --git a/engine/src/flutter/shell/dart/dart_library_provider_files.h b/engine/src/flutter/shell/dart/dart_library_provider_files.h
index 6a3c46cc510..b62751b9fa2 100644
--- a/engine/src/flutter/shell/dart/dart_library_provider_files.h
+++ b/engine/src/flutter/shell/dart/dart_library_provider_files.h
@@ -18,7 +18,7 @@ class DartLibraryProviderFiles : public blink::DartLibraryProvider {
 
  protected:
   // |DartLibraryProvider| implementation:
-  void GetLibraryAsStream(const String& name,
+  void GetLibraryAsStream(const std::string& name,
                           blink::DataPipeConsumerCallback callback) override;
   Dart_Handle CanonicalizeURL(Dart_Handle library, Dart_Handle url) override;
 
diff --git a/engine/src/flutter/shell/dart/dart_library_provider_network.cc b/engine/src/flutter/shell/dart/dart_library_provider_network.cc
index 8138e049e43..f91cac0b122 100644
--- a/engine/src/flutter/shell/dart/dart_library_provider_network.cc
+++ b/engine/src/flutter/shell/dart/dart_library_provider_network.cc
@@ -14,13 +14,13 @@ namespace shell {
 namespace {
 
 mojo::URLLoaderPtr Fetch(mojo::NetworkService* network_service,
-                         const String& url,
+                         const std::string& url,
                          base::Callback<void(mojo::URLResponsePtr)> callback) {
   mojo::URLLoaderPtr loader;
   network_service->CreateURLLoader(GetProxy(&loader));
 
   mojo::URLRequestPtr request = mojo::URLRequest::New();
-  request->url = url.toUTF8();
+  request->url = url;
   request->auto_follow_redirects = true;
   loader->Start(request.Pass(), callback);
 
@@ -32,7 +32,7 @@ mojo::URLLoaderPtr Fetch(mojo::NetworkService* network_service,
 class DartLibraryProviderNetwork::Job {
  public:
   Job(DartLibraryProviderNetwork* provider,
-      const String& name,
+      const std::string& name,
       blink::DataPipeConsumerCallback callback)
       : provider_(provider), callback_(callback), weak_factory_(this) {
     url_loader_ =
@@ -66,7 +66,7 @@ DartLibraryProviderNetwork::~DartLibraryProviderNetwork() {
 }
 
 void DartLibraryProviderNetwork::GetLibraryAsStream(
-    const String& name,
+    const std::string& name,
     blink::DataPipeConsumerCallback callback) {
   jobs_.add(adoptPtr(new Job(this, name, callback)));
 }
diff --git a/engine/src/flutter/shell/dart/dart_library_provider_network.h b/engine/src/flutter/shell/dart/dart_library_provider_network.h
index b1f0add5859..e68a259db8f 100644
--- a/engine/src/flutter/shell/dart/dart_library_provider_network.h
+++ b/engine/src/flutter/shell/dart/dart_library_provider_network.h
@@ -22,7 +22,7 @@ class DartLibraryProviderNetwork : public blink::DartLibraryProvider {
 
  protected:
   // |DartLibraryProvider| implementation:
-  void GetLibraryAsStream(const String& name,
+  void GetLibraryAsStream(const std::string& name,
                           blink::DataPipeConsumerCallback callback) override;
   Dart_Handle CanonicalizeURL(Dart_Handle library, Dart_Handle url) override;