Teach sky_viewer about the new main.dart hotness

sky/engine/public/sky/sky_view.h

Index: sky/engine/public/sky/sky_view.h
diff --git a/sky/engine/public/sky/sky_view.h b/sky/engine/public/sky/sky_view.h
index e8847d797aa41bac555d29e478147af9fb03c616..2621e7d6b4e6279bbc2bef40a9f52ec956c0ea1f 100644
--- a/sky/engine/public/sky/sky_view.h
+++ b/sky/engine/public/sky/sky_view.h
@@ -6,8 +6,10 @@
 #define SKY_ENGINE_PUBLIC_SKY_SKY_VIEW_H_
 
 #include <memory>
+
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
+#include "mojo/services/network/public/interfaces/url_loader.mojom.h"
 #include "skia/ext/refptr.h"
 #include "sky/engine/public/platform/WebCommon.h"
 #include "sky/engine/public/platform/WebURL.h"
@@ -24,10 +26,13 @@ class SkyView {
   static std::unique_ptr<SkyView> Create(SkyViewClient* client);
   ~SkyView();
 
+  const SkyDisplayMetrics& display_metrics() const { return display_metrics_; }
   void SetDisplayMetrics(const SkyDisplayMetrics& metrics);
-  void Load(const WebURL& url);
-
   void BeginFrame(base::TimeTicks frame_time);
+
+  // Sky can either issue the load itself or use an existing response pipe.
+  void Load(const WebURL& url, mojo::URLResponsePtr response = nullptr);
+
   skia::RefPtr<SkPicture> Paint();
   bool HandleInputEvent(const WebInputEvent& event);