Have testAccessCacheMode wait for favicons to load.

 Bug 6330559
 The favicon loads at an arbitrary time and it may or may not
 have been loaded when the number of items loaded is checked.
 Now the test waits for the favicon to finish loading prior
 to considering the URL loaded.

Change-Id: I0a1ad9ca7f9742e454fcdb194dc9bb31fb566c59
1 file changed