Changes Controller to use Tab.getUrl in more places

 Bug: 3342456
 Changes Controller to use Tab.getUrl() and then added empty
 url checks in places like doUpdateVisitedHistory. Tab already takes
 care of filtering URLs, so filtering out most visited URLs is thus
 handled.

Change-Id: Iaf60353d7cb924991c5e0a5adf18074fcf13bfe6
4 files changed