cast: support cursor rendering for tab capture

content/browser/media/capture/cursor_renderer.h

+// Copyright (c) 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_MEDIA_CAPTURE_CURSOR_RENDERER_H_
+#define CONTENT_BROWSER_MEDIA_CAPTURE_CURSOR_RENDERER_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "content/common/content_export.h"
+#include "media/base/video_frame.h"
+#include "ui/gfx/native_widget_types.h"
+
+namespace content {
+
+// CursorRenderer is an interface that can be implememented to do cursor
+// rendering on a video frame

[miu, 2015/10/23 01:55:12]

style nit: Add period at end of sentence.

It's worth noting in this comment that implementations will also listen to mouse
events in a platform-specific way.

[Irfan, 2015/10/26 23:10:31]

Done.

+class CONTENT_EXPORT CursorRenderer {
+ public:
+  virtual ~CursorRenderer() {}
+
+  virtual void Clear() = 0;

[miu, 2015/10/23 01:55:12]

Please document all methods (what they do and/or why they are called).

[Irfan, 2015/10/26 23:10:31]

Done.

+
+  virtual bool Update(const gfx::Rect& region_in_frame) = 0;

[miu, 2015/10/23 01:55:12]

naming consideration: SnapshotCursorState(), or something that says why/when
this method should be called.

[miu, 2015/10/23 01:55:12]

Please document.  Something like: "Determines whether the cursor will be
rendered, which cursor image to render, and at what location in
|region_in_frame| to render it."

[Irfan, 2015/10/26 23:10:31]

Done.

[Irfan, 2015/10/26 23:10:31]

Done.

+
+  virtual void RenderOnVideoFrame(
+      const scoped_refptr<media::VideoFrame>& target) const = 0;
+
+  virtual base::WeakPtr<CursorRenderer> GetWeakPtr() = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_MEDIA_CAPTURE_CURSOR_RENDERER_H_