Pepper: Remove unused ppapi.gypi file.

ppapi/ppapi.gypi

-# Copyright (c) 2010 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': {
-    #
-    # ppp_entrypoints_sources is a set of source files that provide
-    # a default implementation of plugin entry-points as defined in
-    # ppp.h. Note that these source files assume that plugin is dependent
-    # on ppapi_cpp_objects target defined in ppapi.gyp.
-    #
-    # Note that we cannot compile these source files into a static library
-    # because the entry points need to be exported from the plugin.
-    #
-    'ppp_entrypoints_sources': [
-      '<(DEPTH)/ppapi/cpp/module_embedder.h',
-      '<(DEPTH)/ppapi/cpp/ppp_entrypoints.cc',
-    ],
-  },
-}