Fix flakiness in FileManager SuggestAppDialog test

Fix flakiness in FileManager SuggestAppDialog test

Yeah, I forgot to update test in the previous patch :/
https://chromium.googlesource.com/chromium/src/+/0c71fc50716dcf2fef839bde83ef09287c64202b
(which changed the element to which show-spinner class was applied)

BUG=479757
TEST=Run the test locally

Committed: https://crrev.com/275e7a7a9acc2cd8ed471c66775f766d3d956515
Cr-Commit-Position: refs/heads/master@{#326801}

[tbarzic, 2015-04-24 00:20:42]

tbarzic@chromium.org changed reviewers:
+ yoshiki@chromium.org

[yoshiki, 2015-04-24 08:10:23]

lgtm. Thank you for doing this!

[tbarzic, 2015-04-24 14:56:30]

The CQ bit was checked by tbarzic@chromium.org

[commit-bot: I haz the power, 2015-04-24 14:57:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1105783002/1

[commit-bot: I haz the power, 2015-04-24 15:27:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-24 15:28:18]

Patchset 1 (id:??) landed as
https://crrev.com/275e7a7a9acc2cd8ed471c66775f766d3d956515
Cr-Commit-Position: refs/heads/master@{#326801}