Remove Skia GYP files from Chromium tree.

skia/chromium_skia_defines.gypi

-# Copyright 2014 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-{
-  'variables': {
-
-    # This is a place for defines which will hold out Skia changes.
-    #
-    # When Skia needs to make a change which will affect Chromium, a define may
-    # be added here, the Skia change made behind this define, then Skia rolled
-    # into Chromium. At this point the Chromium side change can be made while
-    # also removing the define. After this Skia can remove the code behind the
-    # now no longer needed define.
-    #
-    # Examples of these sorts of changes are Skia API changes and Skia changes
-    # which will affect blink baselines.
-    #
-    # The intent is that the defines here are transient. Every effort should be
-    # made to remove these defines as soon as practical. This is in contrast to
-    # defines in SkUserConfig.h which are normally more permanent.
-    'chromium_skia_defines': [
-      'SK_IGNORE_DW_GRAY_FIX',
-    ],
-  },
-}