Revert of Revert of Make ninja display elapsed compile time by default.

scripts/slave/compile.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.
 
 """A tool to build chrome, executed by buildbot.
 
   When this is run, the current directory (cwd) should be the outer build
   directory (e.g., chrome-release/build/).
 
@@ skipping 711 matching lines @@
 
   goma_teardown(options, env)
 
   return result
 
 def main_ninja(options, args):
   """Interprets options, clobbers object files, and calls ninja."""
 
   # Prepare environment.
   env = EchoDict(os.environ)
+  env.setdefault('NINJA_STATUS', '[%s/%t | %e] ')
   orig_compiler = options.compiler
   goma_ready = goma_setup(options, env)
   if not goma_ready:
     assert options.compiler not in ('goma', 'goma-clang')
     assert options.goma_dir is None
 
   # ninja is different from all the other build systems in that it requires
   # most configuration to be done at gyp time. This is why this function does
   # less than the other comparable functions in this file.
   print 'chdir to %s' % options.src_dir
@@ skipping 493 matching lines @@
   options.target_output_dir = get_target_build_dir(options.build_tool,
       options.src_dir, options.target, 'iphoneos' in args)
   options.clobber = (options.clobber or
       landmines_triggered(options.target_output_dir))
 
   return main(options, args)
 
 
 if '__main__' == __name__:
   sys.exit(real_main())