android_webview: stop using system ashmem.

third_party/ashmem/ashmem.gyp

 # Copyright (c) 2011 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.
 
 {
   'targets': [
     {
       'target_name': 'ashmem',
-      'conditions': [
-        ['android_webview_build==1', {
-          # WebView must use the Android system version of ashmem to avoid
-          # linking problems.
-          'type': 'none',
-          'variables': {
-            'headers_root_path': '.',
-            'header_filenames': [ 'ashmem.h' ],
-            'shim_generator_additional_args': [
-              '--prefix', 'cutils/',
-            ],
-          },
-          'includes': [
-            '../../build/shim_headers.gypi',
-          ],
-          'link_settings': {
-            'libraries': [
-              '-lcutils',
-            ],
-          },
-        }, {
-          'type': 'static_library',
-          'sources': [
-            'ashmem.h',
-            'ashmem-dev.c'
-          ],
-        }],
+      'type': 'static_library',
+      'sources': [
+        'ashmem.h',
+        'ashmem-dev.c'
       ],
     },
   ],
 }