- makes device contexts opaque to the plugin
- can get / set multiple attributes and flush with a single call (and underlying IPC message exchange)
- currently works in parallel with old API
- adapted pepper test plugin to use new API if use_new_npdevice_api=1
TEST=trybots, visual confirmation that pepper test plugin works with new API
BUG=none
Review URL: http://codereview.chromium.org/1529005
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@44840 0039d316-1c4b-4281-b951-d872f2087c98