Fix memcheck and dr memory after flakiness dashboard deployment.

I deployed buildbot configuration for uploading data to the
flakiness dashboard but I didn't predict our Dr Memory and
Memcheck bots would fail due to the new flag passed to the test.
Adding the --gtest_output flag to the script will avoid the build
to fail as a workaround.

TBR=andrew@webrtc.org
TESTED=Passing test run using:
src/tools/valgrind-webrtc/webrtc_tests.sh --test audio_decoder_unittests --tool memcheck --target Release --build-dir src/out --gtest_output=xml:audio_decoder_unittests.xml

BUG=

Review URL: https://webrtc-codereview.appspot.com/28999004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7642 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/tools/valgrind-webrtc/webrtc_tests.py b/tools/valgrind-webrtc/webrtc_tests.py
index b8b398b..cc0165e 100755
--- a/tools/valgrind-webrtc/webrtc_tests.py
+++ b/tools/valgrind-webrtc/webrtc_tests.py
@@ -100,6 +100,9 @@
                     help='Argument for --gtest_repeat')
   parser.add_option("--gtest_shuffle", action="store_true", default=False,
                     help="Randomize tests' orders on every iteration.")
+  parser.add_option('', '--gtest_output',
+                    help=('Argument for --gtest_output (ignored but included '
+                          'for compatibility).'))
   parser.add_option('-v', '--verbose', action='store_true', default=False,
                     help='Verbose output - enable debug log messages')
   parser.add_option('', '--tool', dest='valgrind_tool', default='memcheck',