The SimpleJavascriptTests are currently disabled due to the flakiness described in 786313.

Started on the custom backgrounds tests and fixing the previously flaky/disabled tests

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b52cfc05e0aaede354199a14bdb2b78c0b62f0b0

commit b52cfc05e0aaede354199a14bdb2b78c0b62f0b0
Author: Kyle Milka <kmilka@chromium.org>
Date: Wed Aug 22 17:26:33 2018

[NTP] Disable MV iframes for SimpleJavascriptTests

The SimpleJavascriptTests were flaky due to loading/destroying of the
MV iframe. Disabling all iframes for these tests will prevent the
flakiness and the iframes aren't needed by the tests anyway.

Also update some of the tests, as things have changed in the time
they've been disabled.

Bug:  857256 ,  845498 
Change-Id: I98d6f337ab2a5172f5e07648f2df0ce272f25597
Reviewed-on: https://chromium-review.googlesource.com/1183958
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Kristi Park <kristipark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585132}
[modify] https://crrev.com/b52cfc05e0aaede354199a14bdb2b78c0b62f0b0/chrome/browser/resources/local_ntp/local_ntp.js
[modify] https://crrev.com/b52cfc05e0aaede354199a14bdb2b78c0b62f0b0/chrome/browser/ui/search/local_ntp_js_browsertest.cc
[modify] https://crrev.com/b52cfc05e0aaede354199a14bdb2b78c0b62f0b0/chrome/test/data/local_ntp/local_ntp_browsertest.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/26f40744728c84d87789b277e75e29b41e606991

commit 26f40744728c84d87789b277e75e29b41e606991
Author: Kyle Milka <kmilka@chromium.org>
Date: Wed Aug 22 21:09:29 2018

[NTP] Separate custom backgrounds JS tests from general tests

Split existing tests for custom backgrounds out from general
SimpleJavascriptTests. These tests were never being run anways,
as they didn't start with 'test'.

Update local_ntp_browsertest.html with changes from local_ntp.html.

Bug:  857256 
Change-Id: I251abfdc8aec75d896118d4ce0b251831b2bff43
Reviewed-on: https://chromium-review.googlesource.com/1184143
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Kristi Park <kristipark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585245}
[modify] https://crrev.com/26f40744728c84d87789b277e75e29b41e606991/chrome/browser/ui/search/local_ntp_js_browsertest.cc
[add] https://crrev.com/26f40744728c84d87789b277e75e29b41e606991/chrome/test/data/local_ntp/custom_backgrounds_browsertest.js
[modify] https://crrev.com/26f40744728c84d87789b277e75e29b41e606991/chrome/test/data/local_ntp/local_ntp_browsertest.html
[modify] https://crrev.com/26f40744728c84d87789b277e75e29b41e606991/chrome/test/data/local_ntp/local_ntp_browsertest.js
[modify] https://crrev.com/26f40744728c84d87789b277e75e29b41e606991/chrome/test/data/local_ntp/test_utils.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e885cc7afc5f8b87febc1634556d9cc0c3a7f9b9

commit e885cc7afc5f8b87febc1634556d9cc0c3a7f9b9
Author: Kyle Milka <kmilka@chromium.org>
Date: Fri Aug 24 22:21:14 2018

[NTP] Add tests for basic background customization flow

Add tests for the various click events that take place during
NTP background customization.

Bug:  857256 
Change-Id: If6f5e6582cbd1f47a02a19702d69fd6d3024606a
Reviewed-on: https://chromium-review.googlesource.com/1187561
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Kristi Park <kristipark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586022}
[modify] https://crrev.com/e885cc7afc5f8b87febc1634556d9cc0c3a7f9b9/chrome/test/data/local_ntp/custom_backgrounds_browsertest.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/45116fe1dd627abf982b4151e94a08095c7d64fa

commit 45116fe1dd627abf982b4151e94a08095c7d64fa
Author: Kyle Milka <kmilka@chromium.org>
Date: Mon Aug 27 20:24:39 2018

[NTP] Test EmbeddedSearch APIs for custom backgrounds

Check that the embeddedsearch APIs for custom background correctly
update the ThemeBackgroundInfo when called.

Bug:  857256 
Change-Id: I7c71ddbbdc30fa9fbcf4a2afc8387affcc39693c
Reviewed-on: https://chromium-review.googlesource.com/1189082
Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586394}
[modify] https://crrev.com/45116fe1dd627abf982b4151e94a08095c7d64fa/chrome/browser/ui/search/local_ntp_browsertest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/619dd76557fefb1ede18fdd45b9a4119cfca1d96

commit 619dd76557fefb1ede18fdd45b9a4119cfca1d96
Author: Reid Kleckner <rnk@chromium.org>
Date: Tue Aug 28 17:43:05 2018

Revert "[NTP] Test EmbeddedSearch APIs for custom backgrounds"

This reverts commit 45116fe1dd627abf982b4151e94a08095c7d64fa.

Reason for revert: Does not pass in official builds:
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/win%20trunk/builds/91358

Original change's description:
> [NTP] Test EmbeddedSearch APIs for custom backgrounds
> 
> Check that the embeddedsearch APIs for custom background correctly
> update the ThemeBackgroundInfo when called.
> 
> Bug:  857256 
> Change-Id: I7c71ddbbdc30fa9fbcf4a2afc8387affcc39693c
> Reviewed-on: https://chromium-review.googlesource.com/1189082
> Reviewed-by: Kristi Park <kristipark@chromium.org>
> Commit-Queue: Kyle Milka <kmilka@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#586394}

TBR=kristipark@chromium.org,kmilka@chromium.org

Change-Id: I756c849a01dfdda6f1c8074a21e0613fc0062fdc
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  857256 
Reviewed-on: https://chromium-review.googlesource.com/1194571
Reviewed-by: Reid Kleckner <rnk@chromium.org>
Commit-Queue: Reid Kleckner <rnk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586774}
[modify] https://crrev.com/619dd76557fefb1ede18fdd45b9a4119cfca1d96/chrome/browser/ui/search/local_ntp_browsertest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/02ccb917271471bbe15bfbad744ff60184b37689

commit 02ccb917271471bbe15bfbad744ff60184b37689
Author: Kyle Milka <kmilka@chromium.org>
Date: Tue Aug 28 22:47:52 2018

[NTP] Add browser_tests for custom backgrounds.

Add a new file for custom backgrounds browser tests.

Test that the background image is correctly set when API calls are made.

Check that the EmbeddedSearch APIs for custom backgrounds correctly
update ThemeBackgroundInfo when called.

Bug:  857256 
Change-Id: I872bbbe22e611e254bb8830e4275ec77bbe6b007
Reviewed-on: https://chromium-review.googlesource.com/1192121
Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586899}
[add] https://crrev.com/02ccb917271471bbe15bfbad744ff60184b37689/chrome/browser/ui/search/local_ntp_backgrounds_browsertest.cc
[modify] https://crrev.com/02ccb917271471bbe15bfbad744ff60184b37689/chrome/test/BUILD.gn
[modify] https://crrev.com/02ccb917271471bbe15bfbad744ff60184b37689/chrome/test/data/local_ntp/custom_backgrounds_browsertest.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/44c4ca24b6633aaed3dd2dea52b587c91a11ec86

commit 44c4ca24b6633aaed3dd2dea52b587c91a11ec86
Author: Weilun Shi <sweilun@chromium.org>
Date: Thu Sep 06 22:01:34 2018

[NTP] Automated test for custom background attribution

Adding automated test for set and reset custom background attribution.
The attribution should be removed when we cleared the custom background
and when a theme was applied.

Bug:  857256 
Change-Id: Iccabe90925bc7e7d3da8ca0fa03705264493cf7b
Reviewed-on: https://chromium-review.googlesource.com/1208469
Commit-Queue: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Kristi Park <kristipark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589324}
[modify] https://crrev.com/44c4ca24b6633aaed3dd2dea52b587c91a11ec86/chrome/browser/ui/search/local_ntp_backgrounds_browsertest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/04d602f53d4e46de7c6c3ccaae94d34d7c356d8b

commit 04d602f53d4e46de7c6c3ccaae94d34d7c356d8b
Author: Weilun Shi <sweilun@chromium.org>
Date: Sat Sep 15 00:50:56 2018

[NTP] Add tests for custom background on offline

When offline, the Chrome Backgrounds option should not show up. Also, if
you turn your network off when you get into the custom background
dialog and click any tile, it should float up an error msg.

Bug:  857256 
Change-Id: Icd5e48897f6dab299521da59c3269ce55a9fa775
Reviewed-on: https://chromium-review.googlesource.com/1227359
Commit-Queue: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Kristi Park <kristipark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591541}
[modify] https://crrev.com/04d602f53d4e46de7c6c3ccaae94d34d7c356d8b/chrome/test/data/local_ntp/custom_backgrounds_browsertest.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7a7bb183353c75c7c6c3055a8f37c07fd8c2571a

commit 7a7bb183353c75c7c6c3055a8f37c07fd8c2571a
Author: Weilun Shi <sweilun@chromium.org>
Date: Sat Sep 15 01:41:29 2018

[NTP] Add automated tests for custom background and gear icon

Adding Automated test for these behaviors:
Gear icon, the background image and the attributions should be changed,
removed or hidden after applying a theme and changing the
default search engine.

Bug:  857256 
Change-Id: I85d3771cbbf8fa412b079324569e20d640db588e
Reviewed-on: https://chromium-review.googlesource.com/1212087
Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Weilun Shi <sweilun@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591554}
[modify] https://crrev.com/7a7bb183353c75c7c6c3055a8f37c07fd8c2571a/chrome/browser/ui/search/local_ntp_backgrounds_browsertest.cc

I think this in pretty good shape. We're adding more as we go.