Fix chrome_tests.sh without -b BUILD_DIR on the Mac

tools/valgrind/chrome_tests.py

 #!/usr/bin/python
 # Copyright (c) 2006-2008 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.
 
 # chrome_tests.py
 
 ''' Runs various chrome tests through valgrind_test.py.
 
 This file is a copy of ../purify/chrome_tests.py. Eventually, it would be nice
@@ skipping 76 matching lines @@
     self._data_dirs = [google.path_utils.ScriptDir()]
 
     if module == "chrome":
       # unfortunately, not all modules have the same directory structure
       self._data_dirs.append(os.path.join(module_dir, "test", "data",
                                           "valgrind"))
     else:
       self._data_dirs.append(os.path.join(module_dir, "data", "valgrind"))
 
     if not self._options.build_dir:
-      dir_chrome = os.path.join(self._source_dir, "sconsbuild", "Debug")
+      builddir = {
+        'darwin': 'xcodebuild',
+        'linux2': 'sconsbuild'
+      }[sys.platform]
+      dir_chrome = os.path.join(self._source_dir, builddir, "Debug")
       dir_module = os.path.join(module_dir, "Debug")
       if exe:
         exe_chrome = os.path.join(dir_chrome, exe)
         exe_module = os.path.join(dir_module, exe)
         if os.path.isfile(exe_chrome) and not os.path.isfile(exe_module):
           self._options.build_dir = dir_chrome
         elif os.path.isfile(exe_module) and not os.path.isfile(exe_chrome):
           self._options.build_dir = dir_module
         elif (os.stat(exe_module)[stat.ST_MTIME] >
               os.stat(exe_chrome)[stat.ST_MTIME]):
@@ skipping 280 matching lines @@
   for t in options.test:
     tests = ChromeTests(options, args, t)
     ret = tests.Run()
     if ret: return ret
   return 0
 
 
 if __name__ == "__main__":
   ret = _main(sys.argv)
   sys.exit(ret)