handle error on no window.parent access
handle error on no window.parent access

Change-Id: I1e46278ef37434c097766e5e2fc1db6e2f6795c1
Reviewed-on: https://gerrit.instructure.com/19341
Reviewed-by: Brad Humphrey <9233b6f5388d6867a2a7be14d8b4ba53c86cfde2@instructure.com>
Reviewed-by: Brian Whitmer <760e7dab2836853c63805033e514668301fa9c47@instructure.com>
Product-Review: Brian Whitmer <760e7dab2836853c63805033e514668301fa9c47@instructure.com>
QA-Review: Brian Whitmer <760e7dab2836853c63805033e514668301fa9c47@instructure.com>
Tested-by: Brian Whitmer <760e7dab2836853c63805033e514668301fa9c47@instructure.com>

whitmer/edu_apps,whitmer/lti_example,whitmer/lti_example,whitmer/edu_apps,whitmer/lti_example