Allow VideoCaptureImpl to suspend/resume frame delivery to its client.

content/renderer/media/video_capture_impl.cc

Index: content/renderer/media/video_capture_impl.cc
===================================================================
--- content/renderer/media/video_capture_impl.cc	(revision 193973)
+++ content/renderer/media/video_capture_impl.cc	(working copy)
@@ -56,6 +56,7 @@
       device_id_(0),
       video_type_(media::VideoCaptureCapability::kI420),
       device_info_available_(false),
+      suspended_(false),
       state_(VIDEO_CAPTURE_STATE_STOPPED) {
   DCHECK(filter);
   memset(&current_params_, 0, sizeof(current_params_));
@@ -138,6 +139,12 @@
                  base::Unretained(this), device_id));
 }
 
+void VideoCaptureImpl::SuspendCapture(bool suspend) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoSuspendCaptureOnCaptureThread,
+                 base::Unretained(this), suspend));
+}
+
 void VideoCaptureImpl::DoDeInitOnCaptureThread(base::Closure task) {
   if (state_ == VIDEO_CAPTURE_STATE_STARTED)
     Send(new VideoCaptureHostMsg_Stop(device_id_));
@@ -275,7 +282,7 @@
     int buffer_id, base::Time timestamp) {
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
 
-  if (state_ != VIDEO_CAPTURE_STATE_STARTED) {
+  if (state_ != VIDEO_CAPTURE_STATE_STARTED || suspended_) {
     Send(new VideoCaptureHostMsg_BufferReady(device_id_, buffer_id));
     return;
   }
@@ -364,6 +371,13 @@
   }
 }
 
+void VideoCaptureImpl::DoSuspendCaptureOnCaptureThread(bool suspend) {
+  DVLOG(1) << "DoSuspendCapture: suspend " << (suspend ? "yes" : "no");
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+
+  suspended_ = suspend;
+}
+
 void VideoCaptureImpl::StopDevice() {
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());