Linux sandbox: move system call sets to sandbox/

Extract system call sets from content/ and move them to sandbox.

This is a re-land of https://codereview.chromium.org/103323003/.

BUG=325535
TBR=jorgelo@chromium.org

Review URL: https://codereview.chromium.org/105913002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238842 0039d316-1c4b-4281-b951-d872f2087c98
Reimplement chrome.principals API through v8 binding

The chrome.principals API was originally implemented in https://codereview.chromium.org/24584002 based on extension system. However since extension does not exist on mobile, we have to reimplement the API through V8 binding.

For background, please refer to the doc https://docs.google.com/a/google.com/document/d/1bVHuWnxjZZrtcwVEJxJEOuD3nZpfvyHxrAQI3mhXZ7U/edit#.

BUG=298164

Review URL: https://codereview.chromium.org/88833002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238843 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238843