Re-arrange OOM killer to account for SERVICE_ADJ and PREVIOUS_APP_ADJ in slots

See: http://forum.xda-developers.com/showpost.php?p=50044022&postcount=1500

Change-Id: I360359c6f073aab7fd7b2e00afa72618120fe006
WebViewClassic: Add freeMemoryForTests

Since the 4.4.3 merge, an override of freeMemoryForTests is required to build

Change-Id: I81c13f4d4f39332ccce3616881ec6e84605ef0ee