Reland of Moving webrtc.gni up one level from build/

webrtc/common_video/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/webrtc.gni")
+import("../webrtc.gni")
 
 config("common_video_config") {
   include_dirs = [
     "include",
     "libyuv/include",
   ]
 }
 
 rtc_static_library("common_video") {
   sources = [
@@ skipping 110 matching lines @@
     if (is_android) {
       deps += [ "//testing/android/native_test:native_test_support" ]
       shard_timeout = 900
     }
 
     if (is_ios) {
       deps += [ ":common_video_unittests_bundle_data" ]
     }
   }
 }