Merge 22284 - Refactoring of master preferences parsing before adding a new p...

Merge 22284 - Refactoring of master preferences parsing before adding a new preference.

Currently we are parsing master preferences file three time on startup. Since we only return an int bit mask flag after parsing preferences, it can not handle any preference other than boolean and we end up reading it again for first run tabs and ping delay. This change refactors all the preferences parsing logic to directly pass around DictionaryValue object around in Chrome as well as installer.

No functional change but this will make adding a new preference for new icon more logical since we will not read the preferences file once again.

BUG=12701
TEST=Make sure all the distribution preferences still work as before.

Review URL: http://codereview.chromium.org/159539

TBR=kuchhal@chromium.org


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=23179