Mozart: Improve internal scene graph representation.

services/gfx/compositor/render/render_frame.h

Index: services/gfx/compositor/render/render_frame.h
diff --git a/services/gfx/compositor/render/render_frame.h b/services/gfx/compositor/render/render_frame.h
index 21cdb77834c50c4ad828e5487bc61d0a818f295a..f9cf8386f5425046eb651c9b9bf43b50b05ce48b 100644
--- a/services/gfx/compositor/render/render_frame.h
+++ b/services/gfx/compositor/render/render_frame.h
@@ -8,40 +8,35 @@
 #include <memory>
 
 #include "base/macros.h"
-#include "mojo/services/gfx/composition/interfaces/hit_tests.mojom.h"
 #include "mojo/services/gfx/composition/interfaces/scheduling.mojom.h"
+#include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkRect.h"
 
 class SkCanvas;
-struct SkPoint;
+class SkPicture;
 
 namespace compositor {
 
-class RenderLayer;
-
-// Describes a sequence of drawing commands to be evaluated as a single pass.
-// Frames are introduced into the render frame at points where blending must
-// occur or where portions of a scene graph may be drawn once into a temporary
-// buffer and used many times.
+// Describes a frame to be rendered.
 //
 // Render objects are thread-safe, immutable, and reference counted via
 // std::shared_ptr.  They have no direct references to the scene graph.
 class RenderFrame {
  public:
-  RenderFrame(const std::shared_ptr<RenderLayer>& root_layer,
+  RenderFrame(const skia::RefPtr<SkPicture>& picture,
               const SkRect& viewport,
               const mojo::gfx::composition::FrameInfo& frame_info);
   ~RenderFrame();
 
   static std::shared_ptr<RenderFrame> Create(
-      const std::shared_ptr<RenderLayer>& root_layer,
+      const skia::RefPtr<SkPicture>& picture,
       const SkRect& viewport,
       const mojo::gfx::composition::FrameInfo& frame_info) {
-    return std::make_shared<RenderFrame>(root_layer, viewport, frame_info);
+    return std::make_shared<RenderFrame>(picture, viewport, frame_info);
   }
 
-  // Gets the root layer of the frame.
-  const std::shared_ptr<RenderLayer>& root_layer() const { return root_layer_; }
+  // Gets the underlying picture to rasterize.
+  const skia::RefPtr<SkPicture>& picture() const { return picture_; }
 
   // Gets the frame's viewport.
   const SkRect& viewport() const { return viewport_; }
@@ -54,13 +49,10 @@ class RenderFrame {
   // Paints the frame to a canvas.
   void Paint(SkCanvas* canvas) const;
 
-  // Performs a hit test on the content of the frame.
-  mojo::gfx::composition::HitTestResultPtr HitTest(const SkPoint& point) const;
-
  private:
   friend class RenderFrameBuilder;
 
-  std::shared_ptr<RenderLayer> root_layer_;
+  skia::RefPtr<SkPicture> picture_;
   SkRect viewport_;
   mojo::gfx::composition::FrameInfo frame_info_;