Revert 152406 - Introduce shared_memory_support media target for PPAPI.

media/shared_memory_support.gypi

-# Copyright (c) 2012 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': {
-    'chromium_code': 1,
-    # These are defined here because we need to build this library both for
-    # the general media pipeline and again for the untrusted NaCl target.
-    'shared_memory_support_sources': [
-      'audio/audio_parameters.cc',
-      'audio/audio_parameters.h',
-      'audio/shared_memory_util.cc',
-      'audio/shared_memory_util.h',
-      'base/audio_bus.cc',
-      'base/audio_bus.h',
-      'base/channel_layout.cc',
-      'base/channel_layout.h',
-      'base/limits.h',
-      'base/media_export.h',
-    ],
-  },
-}