Add sandbox support (issue #524).

- The sandbox is now enabled by default on all platforms. Use the CefSettings.no_sandbox option or the "no-sandbox" command-line flag to disable sandbox support.
- Windows: See cef_sandbox_win.h for requirements to enable sandbox support.
- Windows: If Visual Studio isn't installed in the standard location set the CEF_VCVARS environment variable before running make_distrib.py or automate.py (see msvs_env.bat).
- Linux: For binary distributions a new chrome-sandbox executable with SUID permissions must be placed next to the CEF executable. See https://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment for details on setting up the development environment when building CEF from source code.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1518 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

tools/automate/automate.py

@@ -561,7 +561,9 @@ if any_changed or options.forcebuild:
       command = 'ninja -v -C'
     target = ' cefclient'
     if options.buildtests:
-      target = ' cefclient cef_unittests'
+      target = target + ' cef_unittests'
+    if platform == 'linux':
+      target = target + ' chrome_sandbox'
     build_dir_suffix = ''
     if platform == 'windows' and options.x64build:
       build_dir_suffix = '_x64'