Any ideas, folks? 

It seems like when this navigation happens, there is a call to 

  [PrimaryToolbarViewController updateForSideSwipeSnapshotOnNTP:]

which sets 

  self.view.locationBarContainer.hidden = YES;

But there is no matching call to 

  [PrimaryToolbarViewController resetAfterSideSwipeSnapshot]

Here's the meaningful part of the call stack for the original call: 

* thread #1, name = 'CrWebMain', queue = 'com.apple.main-thread', stop reason = breakpoint 5.1
  * frame #0: 0x0000000106495dcc Chromium`::-[PrimaryToolbarViewController updateForSideSwipeSnapshotOnNTP:](self=0x00007fa416231410, _cmd="updateForSideSwipeSnapshotOnNTP:", onNTP=YES) at primary_toolbar_view_controller.mm:61
    frame #1: 0x00000001061557e1 Chromium`::-[ContentSuggestionsCoordinator start](self=0x0000624000124240, _cmd="start") at content_suggestions_coordinator.mm:159
    frame #2: 0x0000000106d087cc Chromium`::-[NewTabPageController loadPanel:](self=0x00006240001fc900, _cmd="loadPanel:", item=0x000062400005f290) at new_tab_page_controller.mm:324
    frame #3: 0x0000000106d06b37 Chromium`::-[NewTabPageController initWithUrl:loader:focuser:browserState:toolbarDelegate:tabModel:parentViewController:dispatcher:safeAreaInset:](self=0x00006240001fc900, _cmd="initWithUrl:loader:focuser:browserState:toolbarDelegate:tabModel:parentViewController:dispatcher:safeAreaInset:", url=0x00007ffeeadc2118, loader=0x00007fa41880f000, focuser=0x00006240000aa6e0, browserState=0x00007fa420208580, toolbarDelegate=0x000062c0000169b0, tabModel=0x00007fa420018380, parentViewController=0x00007fa4162088b0, dispatcher=0x00006240000aa6e0, safeAreaInset=(top = 0, left = 0, bottom = 0, right = 0)) at new_tab_page_controller.mm:177
    frame #4: 0x0000000106b22310 Chromium`::-[BrowserViewController controllerForURL:webState:](self=0x00007fa41880f000, _cmd="controllerForURL:webState:", url=0x00007ffeeadc2118, webState=0x00007fa414539d80) at browser_view_controller.mm:3757
    frame #5: 0x0000000105ad1403 Chromium`::-[CRWWebController loadNativeContentForNavigationItem:](self=0x00007fa414539f40, _cmd="loadNativeContentForNavigationItem:", item=0x00007fa41f822600) at crw_web_controller.mm:1783
    frame #6: 0x0000000105ad12c5 Chromium`::-[CRWWebController loadCurrentURLInNativeView](self=0x00007fa414539f40, _cmd="loadCurrentURLInNativeView") at crw_web_controller.mm:1773
    frame #7: 0x0000000105ad34c6 Chromium`::-[CRWWebController loadCurrentURL](self=0x00007fa414539f40, _cmd="loadCurrentURL") at crw_web_controller.mm:1912
    frame #8: 0x0000000105bdf274 Chromium`web::WebStateImpl::LoadCurrentItem(this=0x00007fa414539d80) at web_state_impl.mm:830
    frame #9: 0x0000000105a1e6ba Chromium`web::NavigationManagerImpl::FinishLoadURLWithParams(this=0x000061c000478480) at navigation_manager_impl.mm:462
    frame #10: 0x0000000105a1d93c Chromium`web::NavigationManagerImpl::LoadURLWithParams(this=0x000061c000478480, params=0x00007ffeeadc3ad0) at navigation_manager_impl.mm:295
    frame #11: 0x0000000106b27f62 Chromium`::-[BrowserViewController loadURLWithParams:](self=0x00007fa41880f000, _cmd="loadURLWithParams:", params=0x00007ffeeadc3ad0) at browser_view_controller.mm:4281
    frame #12: 0x0000000106396ae7 Chromium`::-[LocationBarCoordinator loadGURLFromLocationBar:transition:](self=0x00006240000df4f0, _cmd="loadGURLFromLocationBar:transition:", url=0x00007ffeeadc4f40, transition=33554433) at 


So I think it's some NTP code that needs to issue the -resetAfterSideSwipeSnapshot call, but please reassign as necessary. 

Important to investigate this. If it's only an edge case, feel free to mark P2

Is this still an issue?  I cannot reproduce this anymore.

The '?' is the important bit that I missed.  Fix in flight.  Thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e9b229cd8b71369bfe70e945a31be9f2969b6327

commit e9b229cd8b71369bfe70e945a31be9f2969b6327
Author: Justin Cohen <justincohen@google.com>
Date: Wed Jun 27 21:49:37 2018

[ios] Show real toolbar on landscape iPhone.

Remove the injected toolbar in the NTP, and shows the real
toolbar when not in split toolbar mode (e.g. landscape iPhone).

Bug:  808431 , 828887,  852443 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ib8cfe87702d7a94b66b9622be1e8bc3049e4c392
Reviewed-on: https://chromium-review.googlesource.com/1113543
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570910}
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/browser_view_controller.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_utils.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_utils_unittest.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_coordinator.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_egtest.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.h
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/content_suggestions/ntp_home_egtest.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/toolbar/adaptive/adaptive_toolbar_view_controller.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/toolbar/adaptive/primary_toolbar_coordinator.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/toolbar/adaptive/primary_toolbar_view_controller.mm
[modify] https://crrev.com/e9b229cd8b71369bfe70e945a31be9f2969b6327/ios/chrome/browser/ui/toolbar/clean/toolbar_mediator.mm

Verified in:

App Version: 69.0.3480.0 canary
Devices: iPads
iOS Version: 11.4, 10.3.3

Location bar is displayed even after navigating to about://newtab?