Converted VideoFrameCapturer callbacks into a VideoFrameCapturer::Delegate interface.

remoting/host/video_frame_capturer.h

Index: remoting/host/video_frame_capturer.h
diff --git a/remoting/host/video_frame_capturer.h b/remoting/host/video_frame_capturer.h
index e2db2b9f7176ae4284d0b3d4fa50b1e7099bc1de..7cc863e79e9119a2c57a4385aab610bc3a440ae8 100644
--- a/remoting/host/video_frame_capturer.h
+++ b/remoting/host/video_frame_capturer.h
@@ -50,13 +50,21 @@ class CaptureData;
 //    Since data can be read while another capture action is happening.
 class VideoFrameCapturer {
  public:
-  // CaptureCompletedCallback is called when the capturer has completed.
-  typedef base::Callback<void(scoped_refptr<CaptureData>)>
-      CaptureCompletedCallback;
-
-  // CursorShapeChangedCallback is called when the cursor shape has changed.
-  typedef base::Callback<void(scoped_ptr<protocol::CursorShapeInfo>)>
-      CursorShapeChangedCallback;
+  // Provides callbacks used by the capturer to pass captured video frames and
+  // mouse cursor shapes to the processing pipeline.
+  class Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    // Called when the capturer has completed. |capture_data| describes
+    // a captured frame.
+    virtual void OnCaptureCompleted(
+        scoped_refptr<CaptureData> capture_data) = 0;
+
+    // Called when the cursor shape has changed.
+    virtual void OnCursorShapeChanged(
+        scoped_ptr<protocol::CursorShapeInfo> cursor_shape) = 0;
+  };
 
   virtual ~VideoFrameCapturer() {}
 
@@ -78,30 +86,27 @@ class VideoFrameCapturer {
   static void EnableXDamage(bool enable);
 #endif  // defined(OS_LINUX)
 
-  // Called at the beginning of a capturing session.
-  virtual void Start(
-      const CursorShapeChangedCallback& callback) = 0;
+  // Called at the beginning of a capturing session. |delegate| must remain
+  // valid until Stop() is called.
+  virtual void Start(Delegate* delegate) = 0;
 
   // Called at the end of a capturing session.
   virtual void Stop() = 0;
 
-  // Return the pixel format of the screen.
+  // Returns the pixel format of the screen.
   virtual media::VideoFrame::Format pixel_format() const = 0;
 
-  // Invalidate the specified region.
+  // Invalidates the specified region.
   virtual void InvalidateRegion(const SkRegion& invalid_region) = 0;
 
-  // Capture the screen data associated with each of the accumulated
-  // dirty region.
-  // When the capture is complete, |callback| is called even if the dirty region
-  // is empty.
+  // Captures the screen data associated with each of the accumulated
+  // dirty region. When the capture is complete, the delegate is notified even
+  // if the dirty region is empty.
   //
   // It is OK to call this method while another thread is reading
-  // data of the previous capture.
-  // There can be at most one concurrent read going on when this
-  // method is called.
-  virtual void CaptureInvalidRegion(
-      const CaptureCompletedCallback& callback) = 0;
+  // data of the previous capture. There can be at most one concurrent read
+  // going on when this method is called.
+  virtual void CaptureInvalidRegion() = 0;
 
   // Get the size of the most recently captured screen.
   virtual const SkISize& size_most_recent() const = 0;