GitLab

This adds a screen reader announcement of "Found X search results for
'Y'" when the user performs a search.

BUG=425625,606527
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2388413002
Cr-Commit-Position: refs/heads/master@{#423062}