NaCl: Stop disabling the sandbox on Linux for testing in nacl_integration

ppapi/native_client/tools/browser_tester/browsertester/browserlauncher.py

 #!/usr/bin/python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os.path
 import re
 import shutil
 import sys
 import tempfile
@@ skipping 268 matching lines @@
             # Unfortunately, the browser tester can randomly choose a
             # blacklisted port.  To work around this, the tester whitelists
             # whatever port it is using.
             '--explicitly-allowed-ports=%d' % port,
             '--user-data-dir=%s' % self.profile]
     # Log network requests to assist debugging.
     cmd.append('--log-net-log=%s' % self.NetLogName())
     if self.options.ppapi_plugin is None:
       cmd.append('--enable-nacl')
       disable_sandbox = False
-      # Sandboxing Chrome on Linux requires a SUIDed helper binary.  This
-      # binary may not be installed, so disable sandboxing to avoid the
-      # corner cases where it may fail.  This is a little scarry, because it
-      # means we are not testing NaCl inside the outer sandbox on Linux.
-      disable_sandbox |= PLATFORM == 'linux'
       # Chrome process can't access file within sandbox
       disable_sandbox |= self.options.nacl_exe_stdin is not None
       disable_sandbox |= self.options.nacl_exe_stdout is not None
       disable_sandbox |= self.options.nacl_exe_stderr is not None
       if disable_sandbox:
         cmd.append('--no-sandbox')
     else:
       cmd.append('--register-pepper-plugins=%s;application/x-nacl'
                  % self.options.ppapi_plugin)
       cmd.append('--no-sandbox')
@@ skipping 21 matching lines @@
              '--trace-children=yes',
              '--nacl-file=%s' % (self.options.files[0],),
              '--ignore=../tools/valgrind/tsan/ignores.txt',
              '--suppressions=../tools/valgrind/tsan/suppressions.txt',
              '--log-file=%s/log.%%p' % (self.tool_log_dir,)] + cmd
     elif self.options.tool != None:
       raise LaunchFailure('Invalid tool name "%s"' % (self.options.tool,))
     cmd.extend(self.options.browser_flags)
     cmd.append(url)
     return cmd