Replace timestamps with affected bool vector. Timestamps could cause
some entries marked as affected on iteration i, to be recalculated
twice on iterations i and i+1. Which is redundant.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/9467002
Patch from Alexei Filippov <alexeif@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10821 ce2b1a6d-e550-0410-aec6-3dcde31c8c00