Add OnRemoved() in VideoCapture::EventHandler API

This is to allow client to know when the event handler can be deleted.

BUG=none
TEST=trybots
Review URL: http://codereview.chromium.org/8037055

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@103016 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 11 insertions, 0 deletions

diff --git a/media/video/capture/video_capture.h b/media/video/capture/video_capture.h
index 9a197e2..c4f6d70 100644
--- a/media/video/capture/video_capture.h
+++ b/media/video/capture/video_capture.h
@@ -66,6 +66,10 @@ class VideoCapture {
     // Notify client that video capture has hit some error |error_code|.
     virtual void OnError(VideoCapture* capture, int error_code) = 0;
 
+    // Notify client that the client has been removed and no more calls will be
+    // received.
+    virtual void OnRemoved(VideoCapture* capture) = 0;
+
     // Notify client that a buffer is available.
     virtual void OnBufferReady(VideoCapture* capture,
                                scoped_refptr<VideoFrameBuffer> buffer) = 0;
@@ -93,10 +97,12 @@ class VideoCapture {
 
   // Request video capture to start capturing with |capability|.
   // Also register |handler| with video capture for event handling.
+  // |handler| must remain valid until it has received |OnRemoved()|.
   virtual void StartCapture(EventHandler* handler,
                             const VideoCaptureCapability& capability) = 0;
 
   // Request video capture to stop capturing for client |handler|.
+  // |handler| must remain valid until it has received |OnRemoved()|.
   virtual void StopCapture(EventHandler* handler) = 0;
 
   // Feed buffer to video capture when done with it.
diff --git a/media/video/capture/video_capture_proxy.cc b/media/video/capture/video_capture_proxy.cc
index 0ee5393..a8d00cb 100644
--- a/media/video/capture/video_capture_proxy.cc
+++ b/media/video/capture/video_capture_proxy.cc
@@ -68,6 +68,10 @@ void VideoCaptureHandlerProxy::OnError(VideoCapture* capture, int error_code) {
       error_code));
 }
 
+void VideoCaptureHandlerProxy::OnRemoved(VideoCapture* capture) {
+  // TODO(vtl): add logic when this event handler is removed.
+}
+
 void VideoCaptureHandlerProxy::OnBufferReady(
     VideoCapture* capture,
     scoped_refptr<VideoCapture::VideoFrameBuffer> buffer) {
diff --git a/media/video/capture/video_capture_proxy.h b/media/video/capture/video_capture_proxy.h
index 8be8474..0594379 100644
--- a/media/video/capture/video_capture_proxy.h
+++ b/media/video/capture/video_capture_proxy.h
@@ -51,6 +51,7 @@ class MEDIA_EXPORT VideoCaptureHandlerProxy
   virtual void OnStopped(VideoCapture* capture) OVERRIDE;
   virtual void OnPaused(VideoCapture* capture) OVERRIDE;
   virtual void OnError(VideoCapture* capture, int error_code) OVERRIDE;
+  virtual void OnRemoved(VideoCapture* capture) OVERRIDE;
   virtual void OnBufferReady(
       VideoCapture* capture,
       scoped_refptr<VideoCapture::VideoFrameBuffer> buffer) OVERRIDE;