[DesktopCapturer] FallbackDesktopCapturerWrapper and its tests

webrtc/modules/desktop_capture/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/ui.gni")
 import("../../webrtc.gni")
@@ skipping 45 matching lines @@
   }
 
   rtc_source_set("desktop_capture_unittests") {
     testonly = true
     sources = [
       "desktop_and_cursor_composer_unittest.cc",
       "desktop_capturer_differ_wrapper_unittest.cc",
       "desktop_frame_rotation_unittest.cc",
       "desktop_region_unittest.cc",
       "differ_block_unittest.cc",
+      "fallback_desktop_capturer_wrapper_unittest.cc",
       "mouse_cursor_monitor_unittest.cc",
       "rgba_color_unittest.cc",
       "test_utils.cc",
       "test_utils.h",
       "test_utils_unittest.cc",
       "win/cursor_unittest.cc",
       "win/cursor_unittest_resources.h",
       "win/cursor_unittest_resources.rc",
     ]
     deps = [
@@ skipping 102 matching lines @@
     "desktop_capturer.cc",
     "desktop_capturer.h",
     "desktop_capturer_differ_wrapper.cc",
     "desktop_capturer_differ_wrapper.h",
     "desktop_frame_rotation.cc",
     "desktop_frame_rotation.h",
     "desktop_frame_win.cc",
     "desktop_frame_win.h",
     "differ_block.cc",
     "differ_block.h",
+    "fallback_desktop_capturer_wrapper.cc",
+    "fallback_desktop_capturer_wrapper.h",
     "mac/desktop_configuration.h",
     "mac/desktop_configuration.mm",
     "mac/desktop_configuration_monitor.cc",
     "mac/desktop_configuration_monitor.h",
     "mac/full_screen_chrome_window_detector.cc",
     "mac/full_screen_chrome_window_detector.h",
     "mac/scoped_pixel_buffer_object.cc",
     "mac/scoped_pixel_buffer_object.h",
     "mac/window_list_utils.cc",
     "mac/window_list_utils.h",
@@ skipping 101 matching lines @@
     sources = [
       "differ_vector_sse2.cc",
       "differ_vector_sse2.h",
     ]
 
     if (is_posix) {
       cflags = [ "-msse2" ]
     }
   }
 }