Video Capture: Allow suspension of individual devices.

media/capture/video/video_capture_device.h

Index: media/capture/video/video_capture_device.h
diff --git a/media/capture/video/video_capture_device.h b/media/capture/video/video_capture_device.h
index cbdc8adde4c6e44dd2d764957a6873c267d02109..ae6565f4422c6ea3c26b37b78f10a307958176cb 100644
--- a/media/capture/video/video_capture_device.h
+++ b/media/capture/video/video_capture_device.h
@@ -167,6 +167,15 @@ class CAPTURE_EXPORT VideoCaptureDevice {
   // reasonable attempts to honor these requests.
   virtual void RequestRefreshFrame() {}
 
+  // Optionally suspends frame delivery. The VideoCaptureDevice may or may not
+  // honor this request. The purpose of this is to quickly place the device into
+  // a state where it's resource utilization is minimized while there are no
+  // frame consumers; and then quickly resume once a frame consumer is present.
+  virtual void MaybeSuspend() {}

[mcasas, 2016/09/28 21:34:44]

Could we say here MaybePause()? It would sound
to  me as the complementary operation of 
Resume(), and sort-of like a VCR recorder. But
I'm no Merriam nor Webster so I'll agree to your view.

+
+  // Resumes frame delivery, if it was suspended.
+  virtual void Resume() {}
+
   // Deallocates the video capturer, possibly asynchronously.
   //
   // This call requires the device to do the following things, eventually: put