Hm, on further investigation, the remote NTP does have RTL support, it just doesn't use the searchBox API to trigger it. So we should fix it for the local NTP.

To test RTL: --force-ui-direction=rtl

...except that doesn't work for the NTP, because that flag currently isn't passed to the renderer process.

Turns out the fix is pretty simple, and the OGB does in fact work correctly (with an actual RTL language, not with the --force-ui-direction flag though). Let's get the fix into 62.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ad33cf94f3251449231decff805b91443635ad87

commit ad33cf94f3251449231decff805b91443635ad87
Author: Marc Treib <treib@chromium.org>
Date: Thu Aug 24 11:19:00 2017

Local NTP: Fix RTL support

Detecting RTL mode depends on embeddedSearch.searchBox.rtl, which was
mistakenly removed in https://codereview.chromium.org/2884293002/.
This adds back that API, so the local NTP can detect RTL-ness again.
It also adds a test to verify that the RTL flag makes it all the way to
the page, plus some plumbing to make the --force-ui-direction flag work
with the NTP.

Bug:  758182 
Change-Id: I3e11d5c00a8ff6bf5e6306cbc3142cd2257460b1
Reviewed-on: https://chromium-review.googlesource.com/631680
Commit-Queue: Marc Treib <treib@chromium.org>
Reviewed-by: Chris Pickel <sfiera@chromium.org>
Cr-Commit-Position: refs/heads/master@{#497004}
[modify] https://crrev.com/ad33cf94f3251449231decff805b91443635ad87/chrome/browser/chrome_content_browser_client.cc
[modify] https://crrev.com/ad33cf94f3251449231decff805b91443635ad87/chrome/browser/ui/search/local_ntp_browsertest.cc
[modify] https://crrev.com/ad33cf94f3251449231decff805b91443635ad87/chrome/renderer/resources/extensions/searchbox_api.js
[modify] https://crrev.com/ad33cf94f3251449231decff805b91443635ad87/chrome/renderer/searchbox/searchbox_extension.cc