[ios] Fixes Infobar presentation for contained BVC.

On M83 the BVC will be contained by the TabGrid rather than being
presented. This requires some updating to the Messages presentation
logic, which is done via this CL.


- BVC now informs the InfobarContainer that it will disappear, when this
happens no Infobar should be presented, until BVC "appears" again.

- Fixes a bug where presenting a Banner while BVC is being dismissed
would cause the Banner to remain on screen since now its presenting
ViewController is not being dismissed. shouldDismissBanner was added
to the InfobarBannerContainer protocol so a banner can ask its container
if it should dismiss itself after being presented.

- On InfobarCoordinator we shouldn't always rely on the baseVC (BVC)
presenting Banners, that's why when dismissing a banner we check
its presentingVC instead of BVC presentedVC, this approach would've been
safer even when BVC wasn't contained.

Bug: 1062245
Change-Id: I1d0641cd6e047a72eea9bec79997da4885d2953c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2160808Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762129}

ios/chrome/browser/ui/browser_view/browser_view_controller.mm

@@ -1509,12 +1509,14 @@ NSString* const kBrowserViewControllerSnackbarCategory =
   // TODO(crbug.com/976411):This should probably move to the BannerVC once/if
   // the dismiss event from BVC is observable.
   if (IsInfobarUIRebootEnabled() &&
-      !base::FeatureList::IsEnabled(kInfobarOverlayUI) &&
-      (self.infobarContainerCoordinator.infobarBannerState !=
-       InfobarBannerPresentationState::NotPresented)) {
+      !base::FeatureList::IsEnabled(kInfobarOverlayUI)) {
+    [self.infobarContainerCoordinator baseViewWillDisappear];
+    if (self.infobarContainerCoordinator.infobarBannerState !=
+        InfobarBannerPresentationState::NotPresented) {
       [self.infobarContainerCoordinator dismissInfobarBannerAnimated:NO
                                                           completion:nil];
     }
+  }
   [_bookmarkInteractionController dismissSnackbar];
   [super viewWillDisappear:animated];
 }

ios/chrome/browser/ui/infobars/banners/infobar_banner_container.h

@@ -12,6 +12,10 @@
 // Called whener an InfobarBannerContained banner has been dismissed.
 - (void)infobarBannerFinishedPresenting;
 
+// YES if the InfobarBannerContainer shouldn't be presenting any InfobarBanners,
+// meaning that the InfobarBanner needs to be dismissed.
+- (BOOL)shouldDismissBanner;
+
 @end
 
 // Infobar banners presented by an InfobarCoordinatorContainer.

ios/chrome/browser/ui/infobars/banners/infobar_banner_view_controller.mm

@@ -309,6 +309,12 @@ const CGFloat kLongPressTimeDurationInSeconds = 0.4;
   [super viewDidAppear:animated];
   [self.metricsRecorder recordBannerEvent:MobileMessagesBannerEvent::Presented];
   self.bannerAppearedTime = [NSDate timeIntervalSinceReferenceDate];
+  // Once the Banner animation has completed check if the banner container
+  // should still present banners.
+  if ([self.infobarBannerContainer shouldDismissBanner]) {
+    [self.presentingViewController dismissViewControllerAnimated:NO
+                                                      completion:nil];
+  }
 }
 
 - (void)viewWillDisappear:(BOOL)animated {

ios/chrome/browser/ui/infobars/coordinators/infobar_coordinator.mm

@@ -461,12 +461,11 @@
   // InfobarDelelgate being destroyed. Trying to dismiss it twice might cause a
   // UIKit crash on iOS12.
   if (!self.bannerIsBeingDismissed &&
-      self.baseViewController.presentedViewController &&
-      self.baseViewController.presentedViewController ==
-          self.bannerViewController) {
+      self.bannerViewController.presentingViewController) {
     self.bannerIsBeingDismissed = YES;
     [self infobarBannerWillBeDismissed:userInitiated];
-    [self.baseViewController dismissViewControllerAnimated:animated
+    [self.bannerViewController.presentingViewController
+        dismissViewControllerAnimated:animated
                            completion:completion];
   } else if (completion) {
     completion();

ios/chrome/browser/ui/infobars/infobar_container_coordinator.h

@@ -32,6 +32,11 @@ class WebState;
 // means the view is now visible and part of the main window hierarchy.
 - (void)baseViewDidAppear;
 
+// Notifies the coordinator that its baseViewController's ViewWillDisappear.
+// This means the view is not visible and no longer part of the main window
+// hierarchy.
+- (void)baseViewWillDisappear;
+
 // YES if an Infobar is being presented for |webState|.
 - (BOOL)isInfobarPresentingForWebState:(web::WebState*)webState;
 

ios/chrome/browser/ui/infobars/infobar_container_coordinator.mm

@@ -55,6 +55,10 @@
     NSMutableArray<InfobarCoordinator*>* infobarCoordinatorsToPresent;
 // If YES, the banner is not shown, but the badge and subsequent modals will be.
 @property(nonatomic, assign) BOOL skipBanner;
+// YES if this container baseViewController is currently visible and part of
+// the view hierarchy.
+@property(nonatomic, assign, getter=isBaseViewControllerVisible)
+    BOOL baseViewControllerVisible;
 
 @end
 
@@ -174,12 +178,17 @@
 }
 
 - (void)baseViewDidAppear {
+  self.baseViewControllerVisible = YES;
   InfobarCoordinator* coordinator =
       [self.infobarCoordinatorsToPresent firstObject];
   if (coordinator)
     [self presentBannerForInfobarCoordinator:coordinator];
 }
 
+- (void)baseViewWillDisappear {
+  self.baseViewControllerVisible = NO;
+}
+
 #pragma mark - ChromeCoordinator
 
 - (MutableCoordinatorArray*)childCoordinators {
@@ -268,6 +277,10 @@
   [self presentNextBannerInQueue];
 }
 
+- (BOOL)shouldDismissBanner {
+  return !self.baseViewControllerVisible;
+}
+
 #pragma mark InfobarCommands
 
 - (void)displayModalInfobar:(InfobarType)infobarType {
@@ -301,7 +314,8 @@
   // return.
   if (!(self.infobarBannerState ==
         InfobarBannerPresentationState::NotPresented) ||
-      (!self.baseViewController.view.window)) {
+      (!self.baseViewController.view.window) ||
+      (!self.baseViewControllerVisible)) {
     [self queueInfobarCoordinatorForPresentation:infobarCoordinator];
     return;
   }