[ios] Don't resize overlay presentation container if insignificant

Upon layout, the container view of the Infobar banner view is resized
to match the size of the banner. But then a subsequently triggered
relayout may have a new banner frame size that is small enough to cause
an infinite loop. Thus, container resizing is only done if the height
and width of the new calculated banner frame are different by more
than 0.01.

Bug: 1129761
Change-Id: I0b397c63763c392e021bcf54fb7c7a2df8f872eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2432661Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814502}

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

@@ -19,6 +19,9 @@ const CGFloat kContainerHorizontalPadding = 8;
 const CGFloat kContainerMaxWidth = 398;
 // The presented view maximum height.
 const CGFloat kContainerMaxHeight = 230;
+// Minimum height or width frame change that should warrant a resizing of the
+// container view in response to a relayout.
+const CGFloat kMinimumSizeChange = 0.01;
 }
 
 @interface InfobarBannerPresentationController ()
@@ -104,8 +107,18 @@ const CGFloat kContainerMaxHeight = 230;
   CGRect bannerFrame = self.bannerFrame;
   UIView* containerView = self.containerView;
   UIWindow* window = containerView.window;
-  containerView.frame = [containerView.superview convertRect:bannerFrame
-                                                    fromView:window];
+
+  CGRect newFrame = [containerView.superview convertRect:bannerFrame
+                                                fromView:window];
+  // Make sure new calculate frame has changed enough to warrant a rerender.
+  // Otherwise, an infinite loop is possible.
+  if (std::fabs(newFrame.size.height - containerView.frame.size.height) >
+          kMinimumSizeChange ||
+      std::fabs(newFrame.size.width - containerView.frame.size.width) >
+          kMinimumSizeChange) {
+    containerView.frame = newFrame;
+  }
+
   UIView* bannerView = self.presentedView;
   bannerView.frame = [bannerView.superview convertRect:bannerFrame
                                               fromView:window];