Add a Record button to the web-app if the host supports video recording.

remoting/host/video_frame_recorder_host_extension.cc

Index: remoting/host/video_frame_recorder_host_extension.cc
diff --git a/remoting/host/video_frame_recorder_host_extension.cc b/remoting/host/video_frame_recorder_host_extension.cc
index b0b4d47d84bdef289c35b713e094c16218172a9c..e5a2e84afc4a226c8815c5a03b9fb4e8aa6a75ef 100644
--- a/remoting/host/video_frame_recorder_host_extension.cc
+++ b/remoting/host/video_frame_recorder_host_extension.cc
@@ -10,6 +10,7 @@
 #include "base/logging.h"
 #include "base/values.h"
 #include "remoting/codec/video_encoder_verbatim.h"
+#include "remoting/host/client_session_control.h"
 #include "remoting/host/host_extension_session.h"
 #include "remoting/host/video_frame_recorder.h"
 #include "remoting/proto/control.pb.h"
@@ -56,8 +57,10 @@ class VideoFrameRecorderHostExtensionSession : public HostExtensionSession {
 };
 
 VideoFrameRecorderHostExtensionSession::VideoFrameRecorderHostExtensionSession(
+    ClientSessionControl* client_session_control,
     int64_t max_content_bytes) : first_frame_(false) {
   video_frame_recorder.SetMaxContentBytes(max_content_bytes);
+  client_session_control->ResetVideoPipeline();
 }
 
 scoped_ptr<VideoEncoder>