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

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")
+import("../../build/webrtc.gni")
 
 use_desktop_capture_differ_sse2 = current_cpu == "x86" || current_cpu == "x64"
 
 rtc_static_library("primitives") {
   sources = [
     "desktop_capture_types.h",
     "desktop_frame.cc",
     "desktop_frame.h",
     "desktop_geometry.cc",
     "desktop_geometry.h",
@@ skipping 258 matching lines @@
     sources = [
       "differ_vector_sse2.cc",
       "differ_vector_sse2.h",
     ]
 
     if (is_posix) {
       cflags = [ "-msse2" ]
     }
   }
 }