Fix positioning test that fails when the anchor is partially visible.

This is causing a failure when testing team is updating its
browser sizes.

R=chrishenry
DELTA=6 (4 added, 0 deleted, 2 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=6206


git-svn-id: http://closure-library.googlecode.com/svn/trunk@2473 0b95b8e8-c90f-11de-9d4f-f947ee5921c8
Fix reference to private property in mockactivitymonitor.

R=chrishenry
DELTA=149 (128 added, 1 deleted, 20 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=6207


git-svn-id: http://closure-library.googlecode.com/svn/trunk@2474 0b95b8e8-c90f-11de-9d4f-f947ee5921c8