[ios] Stops cancelling gestures in presented Infobar Modal.

This tap gesture was preventing the TableView from recognizing some
delegate callback like didSelectRow. Setting cancelsTouchesInView
to NO "forwards" the touch to the TableView successfully.

Bug: 1018341
Change-Id: I249e6795b47d67c168eaf574dfdb765ee1bd6d38
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1911480Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714529}

ios/chrome/browser/ui/infobars/presentation/infobar_modal_presentation_controller.mm

@@ -25,9 +25,14 @@ const CGFloat kContainerCornerRadius = 13.0;
 @implementation InfobarModalPresentationController
 
 - (void)presentationTransitionWillBegin {
+  // Add a gesture recognizer to endEditing (thus hiding the keyboard) if a user
+  // taps outside the keyboard while one its being presented. Set
+  // cancelsTouchesInView to NO so the presented Modal can handle the gesture as
+  // well. (e.g. Selecting a row in a TableViewController.)
   UITapGestureRecognizer* tap =
       [[UITapGestureRecognizer alloc] initWithTarget:self.presentedView
                                               action:@selector(endEditing:)];
+  tap.cancelsTouchesInView = NO;
   [self.containerView addGestureRecognizer:tap];
 }