Make the generated stubs weak. Enable the unittests that had conflicting symbols.

third_party/ffmpeg/generate_stubs.py

 #!/usr/bin/python
 #
 # Copyright (c) 2009 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.
 
 """Creates windows and posix stub files for a given set of signatures.
 
 For libraries that need to be loaded outside of the standard executable startup
 path mechanism, stub files need to be generated for the wanted functions.  In
@@ skipping 359 matching lines @@
       A string with the declaration of the function pointer for the signature.
     """
     return 'static %s (*%s_ptr)(%s) = NULL;' % (signature['return_type'],
                                                 signature['name'],
                                                 ', '.join(signature['params']))
 
   @classmethod
   def StubFunction(cls, signature):
     """Generates a stub function definition for the given signature.
 
+    The function definitions are created with __attribute__((weak)) so that
+    they may be overridden by a real static link or mock versions to be used
+    when testing.
+
     Args:
       signature: The hash representing the function signature.
 
     Returns:
       A string with the stub function definition.
     """
     # Generate the return statement prefix if this is not a void function.
     return_prefix = ''
     if signature['return_type'] != 'void':
       return_prefix = 'return '
 
     # Generate the argument list.
     arguments = [re.split('[\*& ]', arg)[-1].strip() for arg in
                  signature['params']]
     arg_list = ', '.join(arguments)
     if arg_list == 'void':
       arg_list = ''
 
-    return """%(return_type)s %(name)s(%(params)s) {
+    return """extern %(return_type)s %(name)s(%(params)s) __attribute__((weak));
+%(return_type)s %(name)s(%(params)s) {
   %(return_prefix)s%(name)s_ptr(%(arg_list)s);
 }""" % {'return_type': signature['return_type'],
         'name': signature['name'],
         'params': ', '.join(signature['params']),
         'return_prefix': return_prefix,
         'arg_list': arg_list}
 
   @classmethod
   def WriteImplementationPreamble(cls, header_path, outfile):
     """Write the necessary includes for the implementation file.
@@ skipping 438 matching lines @@
     finally:
       if header_file is not None:
         header_file.close()
 
   else:
     raise Error('Should not reach here')
 
 
 if __name__ == '__main__':
   main()