Android: Add chrome-specific dynamic linker.

build/android/gyp/gcc_preprocess.py

 #!/usr/bin/env python
 #
 # Copyright 2013 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.
 
 import optparse
 import os
 import subprocess
 import sys
 
 from util import build_utils
 
 def DoGcc(options):
   build_utils.MakeDirectory(os.path.dirname(options.output))
 
-  gcc_cmd = [
-      'gcc',                 # invoke host gcc.
+  gcc_cmd = [ 'gcc' ]  # invoke host gcc.
+  if options.defines:
+    gcc_cmd.extend(sum(map(lambda w: ['-D', w], options.defines), []))
+  gcc_cmd.extend([
       '-E',                  # stop after preprocessing.
       '-D', 'ANDROID',       # Specify ANDROID define for pre-processor.
       '-x', 'c-header',      # treat sources as C header files
       '-P',                  # disable line markers, i.e. '#line 309'
       '-I', options.include_path,
       '-o', options.output,
       options.template
-      ]
+      ])
 
   build_utils.CheckCallDie(gcc_cmd)
 
 
 def main(argv):
   parser = optparse.OptionParser()
   parser.add_option('--include-path', help='Include path for gcc.')
   parser.add_option('--template', help='Path to template.')
   parser.add_option('--output', help='Path for generated file.')
   parser.add_option('--stamp', help='Path to touch on success.')
+  parser.add_option('--defines', help='Pre-defines macros', action='append')
 
   # TODO(newt): remove this once http://crbug.com/177552 is fixed in ninja.
   parser.add_option('--ignore', help='Ignored.')
 
   options, _ = parser.parse_args()
 
   DoGcc(options)
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))