[iOS] Prevent Text Zoom from closing FIP unexpectedly

The root cause here was that [textZoomCoordinator stop] was being
called as part of some routine cleanup, and -stop was dismissing the
presenter, despite the presenter not presenting the coordinator's VC.
Now, the coordinator only dismisses the presenter if it is presenting
its own VC.

Bug: 1067526
Change-Id: I06372272f0651a36dec2e7bfdf18fce61d049488
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134256Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#756625}

ios/chrome/browser/ui/find_bar/find_bar_coordinator.mm

@@ -62,7 +62,8 @@
 }
 
 - (void)stop {
-  if (!self.presenter.isPresenting) {
+  if (![self.presenter isPresentingViewController:self.findBarController
+                                                      .findBarViewController]) {
     return;
   }
 

ios/chrome/browser/ui/text_zoom/text_zoom_coordinator.mm

@@ -71,6 +71,10 @@
 }
 
 - (void)stop {
+  if (![self.presenter
+          isPresentingViewController:self.textZoomViewController]) {
+    return;
+  }
   // If the Text Zoom UI is still active, the dismiss should be unanimated,
   // because the UI will be brought back later.
   BOOL animated;

ios/chrome/browser/ui/toolbar/accessory/toolbar_accessory_presenter.h

@@ -18,6 +18,8 @@
 
 - (instancetype)init NS_UNAVAILABLE;
 
+- (BOOL)isPresentingViewController:(UIViewController*)viewController;
+
 // Whether the presenter is currently presenting a view
 @property(nonatomic, readonly, getter=isPresenting) BOOL presenting;
 

ios/chrome/browser/ui/toolbar/accessory/toolbar_accessory_presenter.mm

@@ -72,6 +72,11 @@ const CGFloat kAnimationDuration = 0.15;
   return self;
 }
 
+- (BOOL)isPresentingViewController:(UIViewController*)viewController {
+  return self.presenting && self.presentedViewController &&
+         self.presentedViewController == viewController;
+}
+
 - (void)prepareForPresentation {
   self.presenting = YES;
   self.backgroundView = [self createBackgroundView];