[Chromoting] Allow ProcessStatsSender to receive nullptr ProcessStatsAgent

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")
 import("//remoting/remoting_options.gni")
 import("//media/media_options.gni")
 
 static_library("protocol") {
   sources = [
@@ skipping 248 matching lines @@
 static_library("test_support") {
   testonly = true
 
   sources = [
     "fake_authenticator.cc",
     "fake_authenticator.h",
     "fake_connection_to_host.cc",
     "fake_connection_to_host.h",
     "fake_datagram_socket.cc",
     "fake_datagram_socket.h",
+    "fake_process_stats_stub.cc",
+    "fake_process_stats_stub.h",
     "fake_session.cc",
     "fake_session.h",
     "fake_stream_socket.cc",
     "fake_stream_socket.h",
     "fake_video_renderer.cc",
     "fake_video_renderer.h",
     "protocol_mock_objects.cc",
     "protocol_mock_objects.h",
   ]
 
@@ skipping 66 matching lines @@
     ]
   }
 
   deps = [
     ":test_support",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }