Page acts as zoomed even when it is not on visionOS.

https://bugs.webkit.org/show_bug.cgi?id=258991
rdar://111176298

Reviewed by Wenson Hsieh.

visionOS is at a constant scale factor, and scales coming from WebCore need to be compared with
WebKit::scalesAreEssentiallyEqual, not traditional comparison operators because
WebCore stores the page scale factor as float instead of double. When we get a scale from WebCore,
we need to ignore differences that are within a small rounding error, with enough leeway
to handle rounding differences that may result from round-tripping through UIScrollView.

* Source/WebKit/UIProcess/API/ios/WKWebViewIOS.mm:
(-[WKWebView _updateScrollViewForTransaction:]):

Canonical link: https://commits.webkit.org/265864@main

Source/WebKit/UIProcess/API/ios/WKWebViewIOS.mm

@@ -928,7 +928,7 @@ - (void)_updateScrollViewForTransaction:(const WebKit::RemoteLayerTreeTransactio
     WebKit::ScrollingTreeScrollingNodeDelegateIOS::updateScrollViewForOverscrollBehavior(_scrollView.get(), horizontalOverscrollBehavior, verticalOverscrollBehavior, WebKit::ScrollingTreeScrollingNodeDelegateIOS::AllowOverscrollToPreventScrollPropagation::No);
 
     bool hasDockedInputView = !CGRectIsEmpty(_inputViewBoundsInWindow);
-    bool isZoomed = layerTreeTransaction.pageScaleFactor() > layerTreeTransaction.initialScaleFactor();
+    bool isZoomed = !WebKit::scalesAreEssentiallyEqual(layerTreeTransaction.pageScaleFactor(), layerTreeTransaction.initialScaleFactor()) && (layerTreeTransaction.pageScaleFactor() > layerTreeTransaction.initialScaleFactor());
 
     bool scrollingNeededToRevealUI = false;
     if (_maximumUnobscuredSizeOverride) {