Connect Sky and Ganesh in SkyShell

sky/shell/gpu/rasterizer.h

Index: sky/shell/gpu/rasterizer.h
diff --git a/sky/shell/gpu/rasterizer.h b/sky/shell/gpu/rasterizer.h
index 8e556418903f0b0b97f3b8d2dc61c33ad2c5355a..3fc8a5aaa4d7a13f62d6d0f52521b84f6d4d2ec0 100644
--- a/sky/shell/gpu/rasterizer.h
+++ b/sky/shell/gpu/rasterizer.h
@@ -34,11 +34,10 @@ class Rasterizer : public GPUDelegate {
 
   void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget) override;
   void OnOutputSurfaceDestroyed() override;
-
-  void Draw(skia::RefPtr<SkPicture> picture);
+  void Draw(skia::RefPtr<SkPicture> picture) override;
 
  private:
-  bool CreateGLContext();
+  void EnsureGLContext();
   void EnsureGaneshSurface(const gfx::Size& size);
 
   scoped_refptr<gfx::GLShareGroup> share_group_;