[ MimeHandlerView ] Fix an error in test

The |query_index| was not defined and the test was not actually
navigating the test page to the desired URL.

TBR=wjmaclean@chromium.org

Bug: 659750
Change-Id: I8f9658ac80adaa20f3cdceb0c19f799b59f96987
Reviewed-on: https://chromium-review.googlesource.com/c/1448776
Reviewed-by: Ehsan Karamad <ekaramad@chromium.org>
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#628125}
1 file changed