diff --git a/gfx/src/nsFont.h b/gfx/src/nsFont.h
index fb0cdf636142..6276a7d61bf4 100644
--- a/gfx/src/nsFont.h
+++ b/gfx/src/nsFont.h
@@ -123,6 +123,10 @@ struct nsFont {
     return Equals(aOther);
   }
 
+  bool operator!=(const nsFont& aOther) const {
+    return !Equals(aOther);
+  }
+
   bool Equals(const nsFont& aOther) const;
 
   nsFont& operator=(const nsFont& aOther);
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 59923d86b0d9..37ec6111bcbe 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -173,6 +173,7 @@ nsChangeHint nsStyleFont::CalcDifference(const nsStyleFont& aOther) const
   MOZ_ASSERT(mAllowZoom == aOther.mAllowZoom,
              "expected mAllowZoom to be the same on both nsStyleFonts");
   if (mSize != aOther.mSize ||
+      mFont != aOther.mFont ||
       mLanguage != aOther.mLanguage ||
       mExplicitLanguage != aOther.mExplicitLanguage ||
       mMathVariant != aOther.mMathVariant ||
@@ -181,11 +182,6 @@ nsChangeHint nsStyleFont::CalcDifference(const nsStyleFont& aOther) const
     return NS_STYLE_HINT_REFLOW;
   }
 
-  nsChangeHint hint = CalcFontDifference(mFont, aOther.mFont);
-  if (hint) {
-    return hint;
-  }
-
   // XXX Should any of these cause a non-nsChangeHint_NeutralChange change?
   if (mGenericID != aOther.mGenericID ||
       mScriptLevel != aOther.mScriptLevel ||
@@ -229,33 +225,6 @@ nsStyleFont::GetLanguage(nsPresContext* aPresContext)
   return language.forget();
 }
 
-nsChangeHint nsStyleFont::CalcFontDifference(const nsFont& aFont1, const nsFont& aFont2)
-{
-  if ((aFont1.size == aFont2.size) && 
-      (aFont1.sizeAdjust == aFont2.sizeAdjust) && 
-      (aFont1.style == aFont2.style) &&
-      (aFont1.weight == aFont2.weight) &&
-      (aFont1.stretch == aFont2.stretch) &&
-      (aFont1.smoothing == aFont2.smoothing) &&
-      (aFont1.fontlist == aFont2.fontlist) &&
-      (aFont1.kerning == aFont2.kerning) &&
-      (aFont1.synthesis == aFont2.synthesis) &&
-      (aFont1.variantAlternates == aFont2.variantAlternates) &&
-      (aFont1.alternateValues == aFont2.alternateValues) &&
-      (aFont1.featureValueLookup == aFont2.featureValueLookup) &&
-      (aFont1.variantCaps == aFont2.variantCaps) &&
-      (aFont1.variantEastAsian == aFont2.variantEastAsian) &&
-      (aFont1.variantLigatures == aFont2.variantLigatures) &&
-      (aFont1.variantNumeric == aFont2.variantNumeric) &&
-      (aFont1.variantPosition == aFont2.variantPosition) &&
-      (aFont1.fontFeatureSettings == aFont2.fontFeatureSettings) &&
-      (aFont1.languageOverride == aFont2.languageOverride) &&
-      (aFont1.systemFont == aFont2.systemFont)) {
-    return NS_STYLE_HINT_NONE;
-  }
-  return NS_STYLE_HINT_REFLOW;
-}
-
 static bool IsFixedData(const nsStyleSides& aSides, bool aEnumOK)
 {
   NS_FOR_CSS_SIDES(side) {
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index 3ab24d7ff363..2a8f87737a55 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -117,7 +117,6 @@ struct nsStyleFont {
            nsChangeHint_ReflowChangesSizeOrPosition |
            nsChangeHint_ClearAncestorIntrinsics;
   }
-  static nsChangeHint CalcFontDifference(const nsFont& aFont1, const nsFont& aFont2);
 
   /**
    * Return aSize multiplied by the current text zoom factor (in aPresContext).