[ios] Call stop on primary toolbar coordinator.

|locationBarCoordinator| needs to disconnect itself from webStateList.
Without this, closing the last incognito tab will DCHECK.

Also adds stop/disconnect/nil to adaptive toolbar coordinator.

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ia631150a73cdb2975fc0592ec5840692bf906d02
Reviewed-on: https://chromium-review.googlesource.com/973686
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545042}

ios/chrome/browser/ui/toolbar/adaptive/adaptive_toolbar_coordinator.mm

@@ -71,6 +71,13 @@
       toolbarButton:self.viewController.toolsMenuButton];
 }
 
+- (void)stop {
+  [super stop];
+  self.toolsMenuButtonObserverBridge = nil;
+  [self.mediator disconnect];
+  self.mediator = nil;
+}
+
 #pragma mark - SideSwipeToolbarSnapshotProviding
 
 - (UIImage*)toolbarSideSwipeSnapshotForWebState:(web::WebState*)webState {

ios/chrome/browser/ui/toolbar/adaptive/primary_toolbar_coordinator.mm

@@ -78,6 +78,11 @@
       ->AddObserver(_fullscreenObserver.get());
 }
 
+- (void)stop {
+  [super stop];
+  [self.locationBarCoordinator stop];
+}
+
 #pragma mark - PrimaryToolbarCoordinator
 
 - (id<VoiceSearchControllerDelegate>)voiceSearchDelegate {