--- a/gfx/thebes/gfxContext.cpp
+++ b/gfx/thebes/gfxContext.cpp
@@ -746,29 +746,16 @@ gfxContext::GetPattern()
   } else if (state.sourceSurface) {
     NS_ASSERTION(false, "Ugh, this isn't good.");
   } else {
     pat = new gfxPattern(state.color);
   }
   return pat.forget();
 }
 
-void
-gfxContext::SetFontSmoothingBackgroundColor(const Color& aColor)
-{
-  CURRENTSTATE_CHANGED()
-  CurrentState().fontSmoothingBackgroundColor = aColor;
-}
-
-Color
-gfxContext::GetFontSmoothingBackgroundColor()
-{
-  return CurrentState().fontSmoothingBackgroundColor;
-}
-
 // masking
 void
 gfxContext::Mask(SourceSurface* aSurface, Float aAlpha, const Matrix& aTransform)
 {
   Matrix old = mTransform;
   Matrix mat = aTransform * mTransform;
 
   ChangeTransform(mat);

--- a/gfx/thebes/gfxContext.h
+++ b/gfx/thebes/gfxContext.h
@@ -277,23 +277,16 @@ public:
     void SetSource(gfxASurface *surface, const gfxPoint& offset = gfxPoint(0.0, 0.0));
 
     /**
      * Uses a pattern for drawing.
      */
     void SetPattern(gfxPattern *pattern);
 
     /**
-     * Set the color that text drawn on top of transparent pixels should be
-     * anti-aliased into.
-     */
-    void SetFontSmoothingBackgroundColor(const mozilla::gfx::Color& aColor);
-    mozilla::gfx::Color GetFontSmoothingBackgroundColor();
-
-    /**
      * Get the source pattern (solid color, normal pattern, surface, etc)
      */
     already_AddRefed<gfxPattern> GetPattern();
 
     /**
      ** Painting
      **/
     /**

--- a/gfx/thebes/gfxFont.h
+++ b/gfx/thebes/gfxFont.h
@@ -2293,17 +2293,16 @@ protected:
 // are dependent on the specific font, so they are set per GlyphRun.
 
 struct MOZ_STACK_CLASS TextRunDrawParams {
     RefPtr<mozilla::gfx::DrawTarget> dt;
     gfxContext              *context;
     gfxFont::Spacing        *spacing;
     gfxTextRunDrawCallbacks *callbacks;
     mozilla::SVGContextPaint *runContextPaint;
-    mozilla::gfx::Color      fontSmoothingBGColor;
     mozilla::gfx::Float      direction;
     double                   devPerApp;
     nscolor                  textStrokeColor;
     gfxPattern              *textStrokePattern;
     const mozilla::gfx::StrokeOptions *strokeOpts;
     const mozilla::gfx::DrawOptions   *drawOpts;
     DrawMode                 drawMode;
     bool                     isVerticalRun;

--- a/gfx/thebes/gfxTextRun.cpp
+++ b/gfx/thebes/gfxTextRun.cpp
@@ -674,18 +674,16 @@ gfxTextRun::Draw(Range aRange, gfx::Poin
     params.textStrokePattern = aParams.textStrokePattern;
     params.drawOpts = aParams.drawOpts;
     params.drawMode = aParams.drawMode;
     params.callbacks = aParams.callbacks;
     params.runContextPaint = aParams.contextPaint;
     params.paintSVGGlyphs = !aParams.callbacks ||
         aParams.callbacks->mShouldPaintSVGGlyphs;
     params.dt = aParams.context->GetDrawTarget();
-    params.fontSmoothingBGColor =
-        aParams.context->GetFontSmoothingBackgroundColor();
 
     GlyphRunIterator iter(this, aRange);
     gfxFloat advance = 0.0;
 
     while (iter.NextRun()) {
         gfxFont *font = iter.GetGlyphRun()->mFont;
         uint32_t start = iter.GetStringStart();
         uint32_t end = iter.GetStringEnd();

--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -7087,20 +7087,17 @@ nsTextFrame::PaintText(const PaintTextPa
   params.textStyle = &textPaintStyle;
   params.textColor = foregroundColor;
   params.textStrokeColor = textStrokeColor;
   params.textStrokeWidth = textPaintStyle.GetWebkitTextStrokeWidth();
   params.clipEdges = &clipEdges;
   params.drawSoftHyphen = (GetStateBits() & TEXT_HYPHEN_BREAK) != 0;
   params.contextPaint = aParams.contextPaint;
   params.callbacks = aParams.callbacks;
-  aParams.context->SetFontSmoothingBackgroundColor(
-    Color::FromABGR(StyleFont()->mFont.fontSmoothingBackgroundColor));
   DrawText(range, textBaselinePt, params);
-  aParams.context->SetFontSmoothingBackgroundColor(Color());
 }
 
 static void
 DrawTextRun(const gfxTextRun* aTextRun,
             const gfx::Point& aTextBaselinePt,
             gfxTextRun::Range aRange,
             const nsTextFrame::DrawTextRunParams& aParams)
 {

--- a/layout/xul/nsTextBoxFrame.cpp
+++ b/layout/xul/nsTextBoxFrame.cpp
@@ -521,18 +521,16 @@ nsTextBoxFrame::DrawText(gfxContext&    
         PresContext()->PresShell()->CreateReferenceRenderingContext();
     DrawTarget* refDrawTarget = refContext->GetDrawTarget();
 
     CalculateUnderline(refDrawTarget, *fontMet);
 
     nscolor c = aOverrideColor ? *aOverrideColor : StyleColor()->mColor;
     ColorPattern color(ToDeviceColor(c));
     aRenderingContext.SetColor(Color::FromABGR(c));
-    aRenderingContext.SetFontSmoothingBackgroundColor(
-        Color::FromABGR(StyleFont()->mFont.fontSmoothingBackgroundColor));
 
     nsresult rv = NS_ERROR_FAILURE;
 
     if (mState & NS_FRAME_IS_BIDI) {
       presContext->SetBidiEnabled();
       nsBidiLevel level = nsBidiPresUtils::BidiLevelFromStyle(StyleContext());
       if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
           // We let the RenderText function calculate the mnemonic's
@@ -594,18 +592,16 @@ nsTextBoxFrame::DrawText(gfxContext&    
       fontMet->GetStrikeout(offset, size);
       params.color = strikeColor;
       params.lineSize.height = presContext->AppUnitsToGfxUnits(size);
       params.offset = presContext->AppUnitsToGfxUnits(offset);
       params.decoration = NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH;
       params.style = strikeStyle;
       nsCSSRendering::PaintDecorationLine(this, *drawTarget, params);
     }
-
-    aRenderingContext.SetFontSmoothingBackgroundColor(Color());
 }
 
 void
 nsTextBoxFrame::CalculateUnderline(DrawTarget* aDrawTarget,
                                    nsFontMetrics& aFontMetrics)
 {
     if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
          // Calculate all fields of mAccessKeyInfo which

--- a/layout/xul/tree/nsTreeBodyFrame.cpp
+++ b/layout/xul/tree/nsTreeBodyFrame.cpp
@@ -3056,20 +3056,16 @@ nsTreeBodyFrame::PaintRow(int32_t       
 
   // Paint our borders and background for our row rect.
   nsITheme* theme = nullptr;
   auto appearance = rowContext->StyleDisplay()->mAppearance;
   if (appearance) {
     theme = aPresContext->GetTheme();
   }
 
-  // Save the current font smoothing background color in case we change it.
-  Color originalColor(aRenderingContext.GetFontSmoothingBackgroundColor());
-  aRenderingContext.SetFontSmoothingBackgroundColor(
-    ToDeviceColor(rowContext->StyleFont()->mFont.fontSmoothingBackgroundColor));
   if (theme && theme->ThemeSupportsWidget(aPresContext, nullptr, appearance)) {
     nsRect dirty;
     dirty.IntersectRect(rowRect, aDirtyRect);
     theme->DrawWidgetBackground(&aRenderingContext, this, appearance, rowRect,
                                 dirty);
   } else {
     result &= PaintBackgroundLayer(rowContext, aPresContext, aRenderingContext,
                                    rowRect, aDirtyRect);
@@ -3169,21 +3165,16 @@ nsTreeBodyFrame::PaintRow(int32_t       
         nscoord dummy;
         if (dirtyRect.IntersectRect(aDirtyRect, checkRect))
           result &= PaintCell(aRowIndex, currCol, cellRect, aPresContext,
                               aRenderingContext, aDirtyRect, dummy, aPt,
                               aBuilder);
       }
     }
   }
-  // If we've changed the font smoothing background color for this row, restore
-  // the color to the original one.
-  if (originalColor != aRenderingContext.GetFontSmoothingBackgroundColor()) {
-    aRenderingContext.SetFontSmoothingBackgroundColor(originalColor);
-  }
 
   return result;
 }
 
 DrawResult
 nsTreeBodyFrame::PaintSeparator(int32_t              aRowIndex,
                                 const nsRect&        aSeparatorRect,
                                 nsPresContext*      aPresContext,