Add unit test for the Settings API Bubble.
Refactored the helper functions into views-specific code and rest (so that the non-views code can be used in more places).
Fixed a bug where if you have two extensions simultaneously overwriting settings, the bubble now knows which one is active.
Also prevent the bubble from writing the suppress flag when the user choses to disable the extension (that way they get the bubble again if the extension becomes enabled for some reason).
BUG=356204
R=sky@chromium.org, yoz@chromium.org
TBR=sky
Review URL: https://codereview.chromium.org/
219593002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@261438 0039d316-1c4b-4281-b951-d872f2087c98