Also, if it turns out we need guards on template_url_service under some conditions, we might be missing some.  All uses of template_url_service in search_provider (and friends) should be audited (and maybe all uses in the whole omnibox component).

fwiw, most of the above links have already moved. I guess we want to grep for 'if \((!)?template_url_service'. There are about a dozen currently.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9bdd15dbe7a1233b86b7a1150c7698568775d643

commit 9bdd15dbe7a1233b86b7a1150c7698568775d643
Author: Kevin Bailey <krb@chromium.org>
Date: Wed Feb 28 04:07:49 2018

[omnibox] Better checking of passing null TemplateURLService

Many unit tests pass a null TemplateURLService* to the Omnibox
functions. These functions should be able to handle that. This CL
represents a pass through those functions, making sure that they
either handle a null pointer, or DCHECK.

It also includes a few minor fixes found along the way.

Bug:  804470 
Change-Id: I2e575121d167b0620cd95881466dbd4d47679ade
Reviewed-on: https://chromium-review.googlesource.com/937394
Commit-Queue: Kevin Bailey <krb@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539702}
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/autocomplete_match.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/base_search_provider_unittest.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/bookmark_provider_unittest.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/clipboard_url_provider_unittest.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/contextual_suggestions_service.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/keyword_provider_unittest.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/mock_autocomplete_provider_client.h
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/omnibox_popup_model.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/physical_web_provider_unittest.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/search_provider.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/test_omnibox_client.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/zero_suggest_provider.cc
[modify] https://crrev.com/9bdd15dbe7a1233b86b7a1150c7698568775d643/components/omnibox/browser/zero_suggest_provider_unittest.cc