Update WebrtcFrameScheduler to avoid concurrent captures.

remoting/protocol/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 
 static_library("protocol") {
   sources = [
     "audio_decode_scheduler.cc",
     "audio_decode_scheduler.h",
@@ skipping 308 matching lines @@
     "ppapi_module_stub.cc",
     "pseudotcp_adapter_unittest.cc",
     "session_config_unittest.cc",
     "spake2_authenticator_unittest.cc",
     "ssl_hmac_channel_authenticator_unittest.cc",
     "third_party_authenticator_unittest.cc",
     "v2_authenticator_unittest.cc",
     "validating_authenticator_unittest.cc",
     "video_frame_pump_unittest.cc",
     "webrtc_audio_source_adapter_unittest.cc",
+    "webrtc_frame_scheduler_unittest.cc",
     "webrtc_transport_unittest.cc",
   ]
 
   deps = [
     ":test_support",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }