Remove FontFallbackList::LoadingCustomFonts()

Now the function always returns false, this patch removes it together
with the relevant code paths.

Bug: 441925
Change-Id: I1e7974ca4cf376e3fa57d3afd97cf1b82e029594
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429530
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810880}

third_party/blink/renderer/core/style/computed_style.cc

@@ -292,8 +292,7 @@ ComputedStyle::ComputeDifferenceIgnoringInheritedFirstLineStyle(
     return Difference::kDisplayAffectingDescendantStyles;
   if (!old_style.NonIndependentInheritedEqual(new_style))
     return Difference::kInherited;
-  if (!old_style.LoadingCustomFontsEqual(new_style) ||
-      old_style.JustifyItems() != new_style.JustifyItems())
+  if (old_style.JustifyItems() != new_style.JustifyItems())
     return Difference::kInherited;
   bool non_inherited_equal = old_style.NonInheritedEqual(new_style);
   if (!non_inherited_equal && old_style.ChildHasExplicitInheritance()) {
@@ -563,10 +562,6 @@ bool ComputedStyle::NonIndependentInheritedEqual(
          svg_style_->InheritedEqual(*other.svg_style_);
 }
 
-bool ComputedStyle::LoadingCustomFontsEqual(const ComputedStyle& other) const {
-  return GetFont().LoadingCustomFonts() == other.GetFont().LoadingCustomFonts();
-}
-
 bool ComputedStyle::NonInheritedEqual(const ComputedStyle& other) const {
   // compare everything except the pseudoStyle pointer
   return ComputedStyleBase::NonInheritedEqual(other) &&

third_party/blink/renderer/core/style/computed_style.h

@@ -1156,7 +1156,6 @@ class ComputedStyle : public ComputedStyleBase,
   bool NonInheritedEqual(const ComputedStyle&) const;
   inline bool IndependentInheritedEqual(const ComputedStyle&) const;
   inline bool NonIndependentInheritedEqual(const ComputedStyle&) const;
-  bool LoadingCustomFontsEqual(const ComputedStyle&) const;
   bool InheritedDataShared(const ComputedStyle&) const;
 
   bool HasChildDependentFlags() const { return ChildHasExplicitInheritance(); }

third_party/blink/renderer/core/style/computed_style_diff_functions.json5

@@ -47,10 +47,6 @@
         name: "DiffNeedsReshapeAndFullLayoutAndPaintInvalidation",
         fields_to_diff: ["font"],
         methods_to_diff: [
-          {
-            method: "FontInternal().LoadingCustomFonts()",
-            field_dependencies: ["font"]
-          },
           {
             method: "TextTransform()",
             field_dependencies: ["text-transform"]

third_party/blink/renderer/platform/fonts/font.cc

@@ -615,10 +615,6 @@ LayoutUnit Font::TabWidth(const TabSize& tab_size, LayoutUnit position) const {
   return distance_to_tab_stop;
 }
 
-bool Font::LoadingCustomFonts() const {
-  return font_fallback_list_ && font_fallback_list_->LoadingCustomFonts();
-}
-
 bool Font::IsFallbackValid() const {
   return !font_fallback_list_ || font_fallback_list_->IsValid();
 }

third_party/blink/renderer/platform/fonts/font.h

@@ -232,7 +232,6 @@ class PLATFORM_EXPORT Font {
 
   void WillUseFontData(const String& text) const;
 
-  bool LoadingCustomFonts() const;
   bool IsFallbackValid() const;
 
   bool ShouldSkipDrawing() const {

third_party/blink/renderer/platform/fonts/font_fallback_list.cc

@@ -80,13 +80,6 @@ void FontFallbackList::ReleaseFontData() {
   shape_cache_.reset();  // Clear the weak pointer to the cache instance.
 }
 
-bool FontFallbackList::LoadingCustomFonts() const {
-  // This function is only used for style and layout invalidation purposes. We
-  // don't need it for invalidation when the feature below is enabled.
-  // TODO(xiaochengh): Remove this function.
-  return false;
-}
-
 bool FontFallbackList::ShouldSkipDrawing() const {
   // The DCHECK hit will be fixed by the runtime enabled feature below, so we
   // don't fix it in the legacy code paths.

third_party/blink/renderer/platform/fonts/font_fallback_list.h

@@ -71,7 +71,6 @@ class PLATFORM_EXPORT FontFallbackList : public RefCounted<FontFallbackList> {
   // revalidate a FontFallbackList, but create a new FontFallbackList instead.
   void RevalidateDeprecated();
 
-  bool LoadingCustomFonts() const;
   bool ShouldSkipDrawing() const;
 
   FontSelector* GetFontSelector() const { return font_selector_.Get(); }