[ios] Removed PageZoomState::IsLegacyFormat as unneeded.

BUG=579697

Review URL: https://codereview.chromium.org/1791443003

Cr-Commit-Position: refs/heads/master@{#383372}

4 files changed, 2 insertions, 17 deletions

diff --git a/ios/web/public/web_state/page_display_state.h b/ios/web/public/web_state/page_display_state.h
index 7098e2f..a9e8802 100644
--- a/ios/web/public/web_state/page_display_state.h
+++ b/ios/web/public/web_state/page_display_state.h
@@ -53,12 +53,6 @@ class PageZoomState {
   // are NAN and the zoom scale is greater than zero.
   bool IsValid() const;
 
-  // PageScrollStates restored from the legacy serialization format make
-  // assumptions about the web view's implementation of zooming, and contain a
-  // non-NAN zoom scale and a NAN minimum and maximum scale.  Legacy zoom scales
-  // can only be applied to CRWUIWebViewWebControllers.
-  bool IsLegacyFormat() const;
-
   // Returns the allowed zoom scale range for this scroll state.
   double GetMinMaxZoomDifference() const {
     return maximum_zoom_scale_ - minimum_zoom_scale_;
diff --git a/ios/web/public/web_state/page_display_state.mm b/ios/web/public/web_state/page_display_state.mm
index 6837ecb..0c8a9ce 100644
--- a/ios/web/public/web_state/page_display_state.mm
+++ b/ios/web/public/web_state/page_display_state.mm
@@ -56,18 +56,12 @@ PageZoomState::~PageZoomState() {
 }
 
 bool PageZoomState::IsValid() const {
-  return IsLegacyFormat() ||
-         (!std::isnan(minimum_zoom_scale_) &&
+  return (!std::isnan(minimum_zoom_scale_) &&
           !std::isnan(maximum_zoom_scale_) && !std::isnan(zoom_scale_) &&
           zoom_scale_ >= minimum_zoom_scale_ &&
           zoom_scale_ <= maximum_zoom_scale_);
 }
 
-bool PageZoomState::IsLegacyFormat() const {
-  return std::isnan(minimum_zoom_scale_) && std::isnan(maximum_zoom_scale_) &&
-         zoom_scale_ > 0.0;
-}
-
 bool PageZoomState::operator==(const PageZoomState& other) const {
   return StateValuesAreEqual(minimum_zoom_scale_, other.minimum_zoom_scale_) &&
          StateValuesAreEqual(maximum_zoom_scale_, other.maximum_zoom_scale_) &&
diff --git a/ios/web/web_state/ui/crw_web_controller.mm b/ios/web/web_state/ui/crw_web_controller.mm
index 8739d22..d47b34a 100644
--- a/ios/web/web_state/ui/crw_web_controller.mm
+++ b/ios/web/web_state/ui/crw_web_controller.mm
@@ -3250,7 +3250,7 @@ const NSTimeInterval kSnapshotOverlayTransition = 0.5;
     _applyingPageState = YES;
     web::PageZoomState zoomState =
         currentItem->GetPageDisplayState().zoom_state();
-    if (!zoomState.IsValid() || zoomState.IsLegacyFormat())
+    if (!zoomState.IsValid())
       zoomState = web::PageZoomState(1.0, 1.0, 1.0);
     [self applyWebViewScrollZoomScaleFromZoomState:zoomState];
     _applyingPageState = NO;
diff --git a/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm b/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
index e4c28c9..b451ff1 100644
--- a/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
+++ b/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
@@ -699,9 +699,6 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
   // meta tags of a page may have changed since the state was recorded, so clamp
   // the zoom scale to the current range if necessary.
   DCHECK(zoomState.IsValid());
-  // Legacy-format scroll states cannot be applied to WKWebViews.
-  if (zoomState.IsLegacyFormat())
-    return;
   CGFloat zoomScale = zoomState.zoom_scale();
   if (zoomScale < self.webScrollView.minimumZoomScale)
     zoomScale = self.webScrollView.minimumZoomScale;