+ John for WebViewKvoTest test failures

CRWWebControllerPageScrollStateTest are flaky on all platforms

I will fix DownloadTaskImplTest

WebViewKvoTest tests use WaitForWebViewLoadCompletionOrTimeout to wait until the navigation is completed, which does not seem to be right. We should use WaitForWebViewContainingTextOrTimeout instead.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cd9d7826f090169c81fbc1595ec7bf31ac186c36

commit cd9d7826f090169c81fbc1595ec7bf31ac186c36
Author: Eugene But <eugenebut@google.com>
Date: Tue Jun 12 21:28:00 2018

Fix DownloadTaskImplTest for iOS 12.

iOS 12 calls private undocumented method from NSHTTPCookieStorage, which
needs to be stubbed in CRWFakeNSURLSessionTask in order to use fake task
with NSHTTPCookieStorage.

Bug:  851472 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I59b676090786a65e902ccd98a5fea85e2b191fed
Reviewed-on: https://chromium-review.googlesource.com/1097570
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566577}
[modify] https://crrev.com/cd9d7826f090169c81fbc1595ec7bf31ac186c36/ios/web/test/fakes/crw_fake_nsurl_session_task.mm

Assigning to John to fix or disable ios/web_view tests for iOS 12.

eugenebut@ DownloadManagerEGTest::testSucessfullDownload is also failing on iOS 12.  Would you like me to create a separate bug for that?

Yes, please. DownloadManagerEGTest::testSucessfullDownload seems like orthogonal to WebViewKvoTest failures.

OK, update bug title for jzw@

I'll take a look. Thanks.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e4b393474c3a9f80e4acaa9cec429dbf652eb218

commit e4b393474c3a9f80e4acaa9cec429dbf652eb218
Author: Justin Cohen <justincohen@google.com>
Date: Thu Jun 14 00:37:59 2018

[ios] Disable failing WebViewKvoTest on iOS12.

Bug:  851472 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ia2adc8be4d6b007eff22acac225c1f6c4952334a
Reviewed-on: https://chromium-review.googlesource.com/1099882
Reviewed-by: John Wu <jzw@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567065}
[modify] https://crrev.com/e4b393474c3a9f80e4acaa9cec429dbf652eb218/ios/web_view/test/web_view_kvo_inttest.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b76fc5cc56b64e75d0ebd7a1c825653fb5a7a1aa

commit b76fc5cc56b64e75d0ebd7a1c825653fb5a7a1aa
Author: John Z Wu <jzw@chromium.org>
Date: Fri Jun 15 20:55:08 2018

Fix WebViewKvoTests by using WaitForWebViewContainingTextOrTimeout.

Navigation may not occur right away after tapping on links, causing
WaitForWebViewLoadCompletionOrTimeout to return immediately.

Bug:  851472 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I5bf173f696dceeebc0118105a74fd0b19ebb27c9
Reviewed-on: https://chromium-review.googlesource.com/1103008
Commit-Queue: John Wu <jzw@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567782}
[modify] https://crrev.com/b76fc5cc56b64e75d0ebd7a1c825653fb5a7a1aa/ios/web_view/test/web_view_kvo_inttest.mm