Revert 245139 "Add libwebm in third_party."

trunk/src/third_party/libwebm/libwebm.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': {
-    'libwebm_sources': [
-      'source/mkvmuxer.cpp',
-      'source/mkvmuxerutil.cpp',
-      'source/mkvwriter.cpp',
-    ],
-  }
-}
-
-if (is_android) {
-  arm_use_neon = false
-  # Our version of arm_neon_optional from common.gypi. This is not used in the
-  # current build so is commented out for now.
-  #arm_optionally_use_neon = false
-} else {
-  arm_use_neon = true
-  #arm_optionally_use_neon = true
-}
-
-if (arm_version == 6) {
-  arm_arch = "armv6"
-  arm_tune = ""
-  arm_float_abi = "softfp"
-  arm_fpu = "vfp"
-  # Thumb is a reduced instruction set available on some ARM processors that
-  # has increased code density.
-  arm_use_thumb = false
-
-} else if (arm_version == 7) {
-  arm_arch = "armv7-a"
-  arm_tune = "cortex-a8"
-  arm_float_abi = "softfp"
-  arm_use_thumb = true
-
-  if (arm_use_neon) {
-    arm_fpu = "neon"
-  } else {
-    arm_fpu = "vfpv3-d16"
-  }
-}