Simplifies standalone VM Android build.

tools/gyp/source_filter.gypi

Index: tools/gyp/source_filter.gypi
===================================================================
--- tools/gyp/source_filter.gypi	(revision 31337)
+++ tools/gyp/source_filter.gypi	(working copy)
@@ -1,15 +0,0 @@
-# Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-# for details. All rights reserved. Use of this source code is governed by a
-# BSD-style license that can be found in the LICENSE file.
-
-{
-  'target_defaults': {
-    'conditions': [
-      ['OS!="android"', {'sources/': [['exclude', '_android\\.(cc|h)$']]}],
-      ['OS!="linux"', {'sources/': [['exclude', '_linux\\.(cc|h)$']]}],
-      ['OS!="mac"', {'sources/': [['exclude', '_macos\\.(cc|h)$']]}],
-      ['OS!="win"', {'sources/': [['exclude', '_win\\.(cc|h)$']]}],
-      ['OS=="win"', {'sources/': [['exclude', '_posix\\.(cc|h)$']]}],
-    ],
-  },
-}