NaCl: have browser_tester set-up the sandbox environment

On Linux, the setuid sandbox needs to be set in the environment.
Fix browser_tester to make use of the test_env script that
sets up the sandbox.

BUG=249900
R=mseaborn@chromium.org

Review URL: https://codereview.chromium.org/17063018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207950 0039d316-1c4b-4281-b951-d872f2087c98

ppapi/native_client/tools/browser_tester/browser_tester.py

@@ -16,6 +16,7 @@ import urllib
 script_dir = os.path.dirname(os.path.abspath(__file__))
 sys.path.append(os.path.join(script_dir, '../../../../third_party/'))
 sys.path.append(os.path.join(script_dir, '../../../../tools/valgrind/'))
+sys.path.append(os.path.join(script_dir, '../../../../testing/'))
 
 import browsertester.browserlauncher
 import browsertester.rpclistener
@@ -24,6 +25,8 @@ import browsertester.server
 import memcheck_analyze
 import tsan_analyze
 
+import test_env
+
 def BuildArgParser():
   usage = 'usage: %prog [options]'
   parser = optparse.OptionParser(usage)
@@ -197,6 +200,9 @@ def RunTestsOnce(url, options):
 
   options.files.append(os.path.join(script_dir, 'browserdata', 'nacltest.js'))
 
+  # Setup the environment with the setuid sandbox path.
+  test_env.enable_sandbox_if_required(os.environ)
+
   # Create server
   host = GetHostName()
   try: