Merge 33379 - Makes the chevron throb after a user sync'ed his bookmarks (if ...

Merge 33379 - Makes the chevron throb after a user sync'ed his bookmarks (if the overflow menu is shown)
This also makes the chevron throb when no bookmarks is added during a sync and merge. 

BUG=24306
TEST=sync with over 10 bookmarks in the bookmark bar so that the chevron is visible.

Patch by Bruno Calvignac<BrunoCalvignac@gmail.com>;
Original Review: http://codereview.chromium.org/306054/show

Review URL: http://codereview.chromium.org/454010

TBR=tim@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=33456