The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/703d781779c52f2b7a77d7b4e44d0c85a1bc1997

commit 703d781779c52f2b7a77d7b4e44d0c85a1bc1997
Author: Sylvain Defresne <sdefresne@chromium.org>
Date: Thu Dec 28 17:45:49 2017

Remove code to display overlay from CRWWebController.

Remove unused code from CRWWebController now that chrome uses
PagePlaceholderTabHelper to display the gray overlay image.

Move the -defaultSnapshotImage implementation to Tab. It will
be moved to SnapshotTabHelper in a followup CL.

Bug:  620939 ,  621250 
Change-Id: I3eede1448ad24a3cc0ec1f6bb257a9d074f917d9
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Reviewed-on: https://chromium-review.googlesource.com/842546
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526303}
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/tabs/tab.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/ui/side_swipe/BUILD.gn
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/ui/side_swipe/DEPS
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/ui/side_swipe/card_side_swipe_view.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/ui/stack_view/BUILD.gn
[delete] https://crrev.com/ebaae6e504b2a989d2b970b7e8b3be467effc7a8/ios/chrome/browser/ui/stack_view/DEPS
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/ui/stack_view/card_set.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/chrome/browser/ui/stack_view/card_set_unittest.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/public/test/fakes/test_web_state.h
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/public/test/fakes/test_web_state.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/public/web_state/ui/crw_web_delegate.h
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/public/web_state/web_state.h
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/web_state/ui/crw_web_controller.h
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/web_state/ui/crw_web_controller.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/web_state/web_state_impl.h
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/web_state/web_state_impl.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/web_state/web_state_impl_unittest.mm
[modify] https://crrev.com/703d781779c52f2b7a77d7b4e44d0c85a1bc1997/ios/web/web_state/web_state_unittest.mm