Enable HTTP loading in Mojo dart content handler

services/dart/dart_app.h

Index: services/dart/dart_app.h
diff --git a/services/dart/dart_app.h b/services/dart/dart_app.h
index c6ab6e3df53743a5e90293040cf20d0f07628d59..d38159bab08162e5b4f5226c5aae1a2174afb8d2 100644
--- a/services/dart/dart_app.h
+++ b/services/dart/dart_app.h
@@ -22,9 +22,14 @@ class ApplicationDelegateImpl;
 
 class DartApp : public mojo::ContentHandlerFactory::HandledApplicationHolder {
  public:
+  // When running from an extracted zip file.
   DartApp(mojo::InterfaceRequest<mojo::Application> application_request,
           const base::FilePath& application_dir,
           bool strict);
+  // When running from a dart file.
+  DartApp(mojo::InterfaceRequest<mojo::Application> application_request,
+          const std::string& url,
+          bool strict);
   virtual ~DartApp();
 
  private: