base

Fix ConcurrentModificationException in SyncManager

ConcurrentModificationException would be thrown because
we didn't break from the for loop after removing an
entry from the collection we were looping over.

Change-Id: I30435670f76f60b238e29658611b06ec789219aa
Bug: 27136502
(cherry picked from commit 12832e3291a66bcab12edd5943767c7827c3f7c6)