Assert that md5sum was built instead of failing silently.

build/android/pylib/android_commands.py

 # Copyright (c) 2012 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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 
 import collections
@@ skipping 600 matching lines @@
     All pushed files can be removed by calling RemovePushedFiles().
     """
     assert os.path.exists(local_path), 'Local path not found %s' % local_path
 
     if not self._md5sum_path:
       default_build_type = os.environ.get('BUILD_TYPE', 'Debug')
       md5sum_path = '%s/%s/md5sum_bin' % (cmd_helper.OutDirectory.get(),
           default_build_type)
       if not os.path.exists(md5sum_path):
         md5sum_path = '%s/Release/md5sum_bin' % cmd_helper.OutDirectory.get()
-        if not os.path.exists(md5sum_path):
-          print >> sys.stderr, 'Please build md5sum.'
-          sys.exit(1)
+        assert os.path.exists(md5sum_path), 'Please build md5sum.'
       command = 'push %s %s' % (md5sum_path, MD5SUM_DEVICE_PATH)
       assert _HasAdbPushSucceeded(self._adb.SendCommand(command))
       self._md5sum_path = md5sum_path
 
     self._pushed_files.append(device_path)
     hashes_on_device = _ComputeFileListHash(
         self.RunShellCommand(MD5SUM_DEVICE_PATH + ' ' + device_path))
     assert os.path.exists(local_path), 'Local path not found %s' % local_path
     hashes_on_host = _ComputeFileListHash(
         subprocess.Popen(
@@ skipping 478 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()