Adding comment to inform the user to set up the sandbox manually on Linux.

tools/run-bisect-manual-test.py

Index: tools/run-bisect-manual-test.py
diff --git a/tools/run-bisect-manual-test.py b/tools/run-bisect-manual-test.py
index 3b69358cb9145dcbc7937968dc3fa9211fd98e19..0e08546bf54a540b269b8e4f263ced51231ddfc4 100755
--- a/tools/run-bisect-manual-test.py
+++ b/tools/run-bisect-manual-test.py
@@ -8,6 +8,11 @@
 An example usage:
 tools/run-bisect-manual-test.py -g 201281 -b 201290
 
+On Linux platform, follow the instructions in this document
+https://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment
+to setup the sandbox manually before running the script. Otherwise the script
+fails to launch Chrome and exits with an error.
+
 """
 
 import os
@@ -109,6 +114,13 @@ def main():
     parser.print_help()
     return 1
 
+  if sys.platform.startswith('linux'):
+    if not os.environ.get('CHROME_DEVEL_SANDBOX'):
+      print 'SUID sandbox has not been setup.'\
+            ' See https://code.google.com/p/chromium/wiki/'\
+            'LinuxSUIDSandboxDevelopment for more information.'
+      return 1
+
   return _RunBisectionScript(options)