allow usage of transparent visuals when using xvfb

testing/xvfb.py

 #!/usr/bin/env python
 # 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.
 
 """Runs tests with Xvfb and Openbox on Linux and normally on other platforms."""
 
 import os
 import platform
 import signal
@@ skipping 63 matching lines @@
     build_dir: The path of the build directory, used for xdisplaycheck.
     xvfb_path: The path to Xvfb.
     display:   The X display number to use.
   """
   assert should_start_xvfb(env)
   assert env.get('_CHROMIUM_INSIDE_XVFB') != '1'
   env['_CHROMIUM_INSIDE_XVFB'] = '1'
   env['DISPLAY'] = display
   xvfb_proc = None
   openbox_proc = None
+  xcompmgr_proc = None
 
   try:
     xvfb_cmd = [xvfb_path, display, '-screen', '0', '1280x800x24', '-ac',
                 '-nolisten', 'tcp', '-dpi', '96']
     xvfb_proc = subprocess.Popen(xvfb_cmd, stdout=subprocess.PIPE,
                                  stderr=subprocess.STDOUT)
 
     if not wait_for_xvfb(os.path.join(build_dir, 'xdisplaycheck'), env):
       rc = xvfb_proc.poll()
       if rc is None:
         print 'Xvfb still running after xdisplaycheck failure, stopping.'
         kill(xvfb_proc)
       else:
         print 'Xvfb exited (code %d) after xdisplaycheck failure.' % rc
       print 'Xvfb output:'
       for l in xvfb_proc.communicate()[0].splitlines():
         print '> %s' % l
-      return (None, None)
+      return (None, None, None)
 
     # Some ChromeOS tests need a window manager.
     openbox_proc = subprocess.Popen('openbox', stdout=subprocess.PIPE,
                                     stderr=subprocess.STDOUT, env=env)
+
+    # Some tests need a compositing manager to make use of transparent visuals.
+    xcompmgr_proc = subprocess.Popen('xcompmgr', stdout=subprocess.PIPE,
+                                     stderr=subprocess.STDOUT, env=env)
   except OSError as e:
-    print >> sys.stderr, 'Failed to start Xvfb or Openbox: %s' % str(e)
+    print >> sys.stderr, 'Failed to start Xvfb or Openbox or xcompmgr: %s' % \
+      str(e)
     kill(xvfb_proc)
     kill(openbox_proc)
-    return (None, None)
+    kill(xcompmgr_proc)
+    return (None, None, None)
 
-  return (xvfb_proc, openbox_proc)
+  return (xvfb_proc, openbox_proc, xcompmgr_proc)
 
 
 def run_executable(cmd, build_dir, env):
   """Runs an executable within Xvfb on Linux or normally on other platforms.
 
   Returns the exit code of the specified commandline, or 1 on failure.
   """
   xvfb = None
   openbox = None
+  xcompmgr = None
   if should_start_xvfb(env):
-    (xvfb, openbox) = start_xvfb(env, build_dir)
-    if not xvfb or not xvfb.pid or not openbox or not openbox.pid:
+    (xvfb, openbox, xcompmgr) = start_xvfb(env, build_dir)
+    if not xvfb or not xvfb.pid or not openbox or not openbox.pid or \
+       not xcompmgr or not xcompmgr.pid:
       return 1
   try:
     return test_env.run_executable(cmd, env)
   finally:
     kill(xvfb)
     kill(openbox)
+    kill(xcompmgr)
 
 
 def main():
   if len(sys.argv) < 3:
     print >> sys.stderr, (
         'Usage: xvfb.py [path to build_dir] [command args...]')
     return 2
   return run_executable(sys.argv[2:], sys.argv[1], os.environ.copy())
 
 
 if __name__ == "__main__":
   sys.exit(main())