Yes, all platforms.

Note: This is cross platform. 

emilyschechter: I'm not sure how to triage this one since this should happen across all platforms. Do we need different bugs per-platform so I can assign?

I think even Android uses the common machinery in template_url_prepopulate_data.cc, so fixing in that file ought to be sufficient for a cross-platform implementation.

I started looking at this to see if I can eliminate the need to re-order China's DSE list (it is the only country I saw where Google is not #1).  But I don't think "find Google's index and use that as default" is the right approach.  If Google is special, why not just let it be special in a clean and simple way by having it first in defaults list?  Zero, top-of-list, first-default -- this is a common pattern, so what value do we gain from complicating it?

This line of code is simple and safe:
https://cs.chromium.org/chromium/src/components/search_engines/template_url_prepopulate_data.cc?rcl=b2432bbba3c089f0f4c117d6a7e57914a49249fb&l=977

But "find Google" will certainly complicate the function and be more likely to have inconsistencies elsewhere... when in doubt, everyone chooses 0, and I don't see a reason to break from that.  So I'd like to close this as WontFix and keep things the way they are, unless someone has a compelling reason to "make Google special, but in a more convoluted way".

Okay, after an offline discussion, it seems there are real-world reasons to do it this way -- I don't understand or agree with them, but reasons exist, so I will go ahead and knock it out today.  Shouldn't be a hard change, might even make branch if approval comes fast.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/28793f213e7eb18316746b2e25afcf8332047fe0

commit 28793f213e7eb18316746b2e25afcf8332047fe0
Author: Orin Jaworski <orinj@chromium.org>
Date: Tue Dec 04 19:31:37 2018

Use google's index for default search provider instead of 0

The default search provider index was always zero before,
and Google was always the first entry, making Google the
default. Now the order won't matter and Google can be put
in the order of usage while remaining the default. For this
CL, Google remains first so it doesn't matter, but this
change will be necessary to keep Google as default when
the order is changed according to new engine usage data.

Bug:  890516 
Change-Id: Iee170b97c9bde3198cdc9094ad2bf55341923766
Reviewed-on: https://chromium-review.googlesource.com/c/1357536
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Kevin Bailey <krb@chromium.org>
Commit-Queue: Orin Jaworski <orinj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613641}
[modify] https://crrev.com/28793f213e7eb18316746b2e25afcf8332047fe0/components/search_engines/template_url_prepopulate_data.cc
[modify] https://crrev.com/28793f213e7eb18316746b2e25afcf8332047fe0/components/search_engines/template_url_prepopulate_data_unittest.cc

For testing: Google is currently #3 in China (CN) and #2 in Russia (RU); #1 elsewhere.  But in Chrome, it should be the default everywhere.