[Mojo Video Capture] Fix VideoCaptureManager exposing implementation details to clients

media/capture/BUILD.gn

 # Copyright 2016 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("//media/media_options.gni")
 import("//testing/test.gni")
 
 group("capture") {
   public_deps = [
@@ skipping 75 matching lines @@
     "video/video_capture_device.h",
     "video/video_capture_device_client.cc",
     "video/video_capture_device_client.h",
     "video/video_capture_device_descriptor.cc",
     "video/video_capture_device_descriptor.h",
     "video/video_capture_device_factory.cc",
     "video/video_capture_device_factory.h",
     "video/video_capture_device_info.cc",
     "video/video_capture_device_info.h",
     "video/video_capture_jpeg_decoder.h",
-    "video/video_capture_system.cc",
     "video/video_capture_system.h",
+    "video/video_capture_system_impl.cc",
+    "video/video_capture_system_impl.h",
     "video/video_frame_receiver.h",
     "video/win/capability_list_win.cc",
     "video/win/capability_list_win.h",
     "video/win/filter_base_win.cc",
     "video/win/filter_base_win.h",
     "video/win/pin_base_win.cc",
     "video/win/pin_base_win.h",
     "video/win/sink_filter_observer_win.h",
     "video/win/sink_filter_win.cc",
     "video/win/sink_filter_win.h",
@@ skipping 106 matching lines @@
       "//media/capture/video/android",
       "//media/capture/video/android:capture_java",
     ]
   }
 
   if (is_win) {
     # TODO(jschuh): https://crbug.com/167187 fix size_t to int truncations.
     configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
   }
 }