enable chromium code for GN, bumping warning level.

BUILD.gn

 # Copyright 2014 The LibYuv 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/arm.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ skipping 61 matching lines @@
     "source/scale.cc",
     "source/scale_any.cc",
     "source/scale_argb.cc",
     "source/scale_common.cc",
     "source/scale_mips.cc",
     "source/scale_gcc.cc",
     "source/scale_win.cc",
     "source/video_common.cc",
   ]
 
-  configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-
-  public_configs = [ ":libyuv_config" ]
+   public_configs = [ ":libyuv_config" ]
 
   defines = []
 
   if (!is_ios) {
     defines += [ "HAVE_JPEG" ]
   }
 
   if (is_msan) {
     # MemorySanitizer does not support assembly code yet.
     # http://crbug.com/344505
@@ skipping 30 matching lines @@
     ]
 
     public_configs = [ ":libyuv_config" ]
 
     if (current_cpu != "arm64") {
       configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
       cflags = [ "-mfpu=neon" ]
     }
   }
 }