[PATCH against-clowncopter] run-tests: add a --profile option

[Augie Fackler]

# HG changeset patch
# User Augie Fackler <augie at google.com>
# Date 1431541326 25200
#      Wed May 13 11:22:06 2015 -0700
# Node ID 21735d2bcefb10605708a1dc640a6cfa590c1361
# Parent  130c305f79910395cbfb73a442cc512605f78bc5
run-tests: add a --profile option

While in the throes of a recent run-tests adventure, I found it useful
to have profiler output for the testrunner itself. Adding it was
simple enough and seems worth keeping around.

diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -240,6 +240,8 @@ def getparser():
                       help='set the given config opt in the test hgrc')
     parser.add_option('--random', action="store_true",
                       help='run tests in random order')
+    parser.add_option('--profile', action='store_true',
+                      help='run statprof on run-tests')
 
     for option, (envvar, default) in defaults.items():
         defaults[option] = type(default)(os.environ.get(envvar, default))
@@ -1653,7 +1655,15 @@ class TestRunner(object):
 
             self._checktools()
             tests = self.findtests(args)
-            return self._run(tests)
+            if options.profile:
+                import statprof
+                statprof.start()
+            result = self._run(tests)
+            if options.profile:
+                statprof.stop()
+                statprof.display()
+            return result
+
         finally:
             os.umask(oldmask)