Use RgbaColor in DesktopFrameGenerator and add RgbaColorTest

webrtc/modules/BUILD.gn

 # Copyright (c) 2016 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/webrtc.gni")
 import("audio_coding/audio_coding.gni")
@@ skipping 500 matching lines @@
       sources += [
         "desktop_capture/desktop_and_cursor_composer_unittest.cc",
         "desktop_capture/desktop_frame_generator.cc",
         "desktop_capture/desktop_frame_generator.h",
         "desktop_capture/fake_desktop_capturer.h",
         "desktop_capture/fake_screen_capturer.cc",
         "desktop_capture/fake_screen_capturer.h",
         "desktop_capture/mouse_cursor_monitor_unittest.cc",
         "desktop_capture/rgba_color.cc",
         "desktop_capture/rgba_color.h",
+        "desktop_capture/rgba_color_unittest.cc",
         "desktop_capture/screen_capturer_differ_wrapper_unittest.cc",
         "desktop_capture/screen_capturer_helper_unittest.cc",
         "desktop_capture/screen_capturer_mac_unittest.cc",
         "desktop_capture/screen_capturer_mock_objects.h",
         "desktop_capture/screen_capturer_unittest.cc",
         "desktop_capture/screen_drawer.h",
         "desktop_capture/screen_drawer_linux.cc",
         "desktop_capture/screen_drawer_mac.cc",
         "desktop_capture/screen_drawer_unittest.cc",
         "desktop_capture/screen_drawer_win.cc",
@@ skipping 138 matching lines @@
       sources += [
         "audio_device/ios/audio_device_unittest_ios.cc",
         "audio_device/ios/objc/RTCAudioSessionTest.mm",
         "video_coding/codecs/h264/h264_video_toolbox_nalu_unittest.cc",
       ]
 
       ldflags = [ "-ObjC" ]
     }
   }
 }