[ios] Improve edge cases for NTP pointer support.

Remove the pointer interaction when the view goes away. Also check the
view is in a window before creating a pointer style.

Bug: 1162914
Change-Id: I2835f453391b291afdce3baabfedf40a3fee10fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627709Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Mike Pinkerton <pinkerton@chromium.org>
Auto-Submit: Mike Pinkerton <pinkerton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843653}

ios/chrome/browser/ui/ntp_tile_views/ntp_tile_view.mm

@@ -23,6 +23,13 @@ const CGFloat kPreferredMaxWidth = 73;
 
 }  // namespace
 
+@interface NTPTileView ()
+// Hold onto the created interaction for pointer support so it can be removed
+// when the view goes away.
+@property(nonatomic, strong)
+    UIPointerInteraction* pointerInteraction API_AVAILABLE(ios(13.4));
+@end
+
 @implementation NTPTileView
 
 - (instancetype)initWithFrame:(CGRect)frame {
@@ -71,14 +78,24 @@ const CGFloat kPreferredMaxWidth = 73;
 
 #ifdef __IPHONE_13_4
     if (@available(iOS 13.4, *)) {
-        [self addInteraction:[[UIPointerInteraction alloc]
-                                 initWithDelegate:self]];
+      _pointerInteraction =
+          [[UIPointerInteraction alloc] initWithDelegate:self];
+      [self addInteraction:self.pointerInteraction];
     }
 #endif
   }
   return self;
 }
 
+- (void)dealloc {
+#ifdef __IPHONE_13_4
+  if (@available(iOS 13.4, *)) {
+    [self removeInteraction:self.pointerInteraction];
+    self.pointerInteraction = nil;
+  }
+#endif
+}
+
 // Returns the font size for the location label.
 - (UIFont*)titleLabelFont {
   return PreferredFontForTextStyleWithMaxCategory(
@@ -111,6 +128,11 @@ const CGFloat kPreferredMaxWidth = 73;
 - (UIPointerStyle*)pointerInteraction:(UIPointerInteraction*)interaction
                        styleForRegion:(UIPointerRegion*)region
     API_AVAILABLE(ios(13.4)) {
+  // The preview APIs require the view to be in a window. Ensure they are before
+  // proceeding.
+  if (!self.window)
+    return nil;
+
   UITargetedPreview* preview =
       [[UITargetedPreview alloc] initWithView:_imageContainerView];
   UIPointerHighlightEffect* effect =