Set working dir for test run script + update resources

By changing the working directory for the executing script to the same
directory as the script is located in, it is possible to run the script
standing in a higher-level directory (otherwise the input file relative
paths become invalid).

This CL also changes the input file path for the audio_e2e_test test to
assume the file is located resources.

BUG=none
TEST=locally executed the tests standing in trunk/

Review URL: https://webrtc-codereview.appspot.com/1061009

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3422 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/test/buildbot_tests.py b/test/buildbot_tests.py
index 0ddb948..a8d8e71 100755
--- a/test/buildbot_tests.py
+++ b/test/buildbot_tests.py
@@ -49,7 +49,7 @@
                       '--gtest_filter=-RtpFuzzTest.*'],
     'audio_e2e_test': ['python',
                        'run_audio_test.py',
-                       '--input=e2e_audio_in.pcm',
+                       '--input=../../resources/e2e_audio_in.pcm',
                        '--output=/tmp/e2e_audio_out.pcm',
                        '--codec=L16',
                        '--compare="~/bin/compare-audio +16000 +wb"',
@@ -97,6 +97,11 @@
       parser.error('Test "%s" is not supported (use --list to view supported '
                    'tests).')
 
+  # Change current working directory to the script's dir to make the relative
+  # paths always work.
+  os.chdir(_CURRENT_DIR)
+  print 'Changed working directory to: %s' % _CURRENT_DIR
+
   print 'Running WebRTC Buildbot tests: %s' % options.test
   for test in options.test:
     cmd_line = test_dict[test]