Add WebrtcVideoEncoder interface

remoting/proto/video.proto

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Protocol for video messages.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
@@ skipping 62 matching lines @@
 
   // Total overhead time for IPC and threading when capturing frames.
   optional int64 capture_overhead_time_ms = 15;
 
   // Time between when the frame was captured and when encoder started encoding
   // it.
   optional int64 encode_pending_time_ms = 16;
 
   // Time for which the frame is blocked until it's sent to the client.
   optional int64 send_pending_time_ms = 17;
-
-  // Indicates whether the encoded frame is a key frame.
-  optional bool key_frame = 18;
 }
 
 // VideoAck acknowledges that the frame in the VideoPacket with the same
 // frame_id has been rendered. VideoAck messages must be sent only for frames
 // that have frame_id field set. They must be sent the same order in which
 // the corresponding VideoPackets were received.
 message VideoAck {
   // Frame ID.
   optional int32 frame_id = 1;
 }