Revert of Move ENABLE_PEPPER_CDMS to a buildflag header.

ppapi/features/BUILD.gn

Index: ppapi/features/BUILD.gn
diff --git a/ppapi/features/BUILD.gn b/ppapi/features/BUILD.gn
deleted file mode 100644
index 8d9a7cbeb196c5742ae73ab50579d2bbe9a0ceef..0000000000000000000000000000000000000000
--- a/ppapi/features/BUILD.gn
+++ /dev/null
@@ -1,16 +0,0 @@
-# Copyright 2016 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.
-
-import("//build/buildflag_header.gni")
-import("//ppapi/features/features.gni")
-
-# This file is in a separate directory so all targets in the build can refer to
-# the buildflag header to get the necessary preprocessor defines without
-# bringing in all of Pepper.
-
-buildflag_header("features") {
-  header = "features.h"
-  flags = [ "ENABLE_PEPPER_CDMS=$enable_pepper_cdms" ]
-}
-