cc: Add OutputSurface state snapshots.

components/display_compositor/buffer_queue.h

Index: components/display_compositor/buffer_queue.h
diff --git a/components/display_compositor/buffer_queue.h b/components/display_compositor/buffer_queue.h
index 6d5a2d33b007f42523ac48a8b75d8400ea572337..8751337f2e103125880a5286ba93233938c4e432 100644
--- a/components/display_compositor/buffer_queue.h
+++ b/components/display_compositor/buffer_queue.h
@@ -11,10 +11,12 @@
 #include <memory>
 #include <vector>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "components/display_compositor/display_compositor_export.h"
 #include "gpu/ipc/common/surface_handle.h"
+#include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/color_space.h"
 #include "ui/gfx/geometry/rect.h"
@@ -63,6 +65,9 @@ class DISPLAY_COMPOSITOR_EXPORT BufferQueue {
 
   void RecreateBuffers();
 
+  void ReadbackDisplayedFramebuffer(SkBitmap* bitmap,
+                                    const base::Callback<void(bool)>& callback);
+
   uint32_t current_texture_id() const {
     return current_surface_ ? current_surface_->texture : 0;
   }