Bug 1501418 - Have scrollbar-color: auto resolved to auto rather than two colors. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D9640

--HG--
extra : moz-landing-system : lando

gfx/src/nsITheme.h

@@ -74,14 +74,6 @@ public:
                                   const nsRect& aRect,
                                   const nsRect& aDirtyRect) = 0;
 
-  /**
-   * Get the used color of the given widget when it's specified as auto.
-   * It's currently only used for scrollbar-*-color properties.
-   */
-  virtual nscolor GetWidgetAutoColor(mozilla::ComputedStyle* aStyle,
-                                     WidgetType aWidgetType)
-  { return NS_RGB(0, 0, 0); }
-
   /**
    * Create WebRender commands for the theme background.
    * @return true if the theme knows how to create WebRender commands for the

layout/style/nsComputedDOMStyle.cpp

@@ -1150,32 +1150,6 @@ nsComputedDOMStyle::SetValueFromComplexColor(nsROCSSPrimitiveValue* aValue,
   SetToRGBAColor(aValue, aColor.CalcColor(mComputedStyle));
 }
 
-void
-nsComputedDOMStyle::SetValueForWidgetColor(nsROCSSPrimitiveValue* aValue,
-                                           const StyleComplexColor& aColor,
-                                           StyleAppearance aWidgetType)
-{
-  if (!aColor.IsAuto()) {
-    SetToRGBAColor(aValue, aColor.CalcColor(mComputedStyle));
-    return;
-  }
-  nsPresContext* presContext = mPresShell->GetPresContext();
-  MOZ_ASSERT(presContext);
-  if (nsContentUtils::ShouldResistFingerprinting(presContext->GetDocShell())) {
-    // Return transparent when resisting fingerprinting.
-    SetToRGBAColor(aValue, NS_RGBA(0, 0, 0, 0));
-    return;
-  }
-  if (nsITheme* theme = presContext->GetTheme()) {
-    nscolor color = theme->GetWidgetAutoColor(mComputedStyle, aWidgetType);
-    SetToRGBAColor(aValue, color);
-  } else {
-    // If we don't have theme, we don't know what value it should be,
-    // just give it a transparent fallback.
-    SetToRGBAColor(aValue, NS_RGBA(0, 0, 0, 0));
-  }
-}
-
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetColor()
 {
@@ -2486,15 +2460,24 @@ already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetScrollbarColor()
 {
   const nsStyleUI* ui = StyleUI();
-  RefPtr<nsDOMCSSValueList> list = GetROCSSValueList(false);
-  auto put = [this, &list](const StyleComplexColor& color,
-                           StyleAppearance type) {
+  MOZ_ASSERT(ui->mScrollbarFaceColor.IsAuto() ==
+             ui->mScrollbarTrackColor.IsAuto(),
+             "Whether the two colors are auto should be identical");
+
+  if (ui->mScrollbarFaceColor.IsAuto()) {
     RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
-    SetValueForWidgetColor(val, color, type);
+    val->SetIdent(eCSSKeyword_auto);
+    return val.forget();
+  }
+
+  RefPtr<nsDOMCSSValueList> list = GetROCSSValueList(false);
+  auto put = [this, &list](const StyleComplexColor& color) {
+    RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+    SetValueFromComplexColor(val, color);
     list->AppendCSSValue(val.forget());
   };
-  put(ui->mScrollbarFaceColor, StyleAppearance::ScrollbarthumbVertical);
-  put(ui->mScrollbarTrackColor, StyleAppearance::ScrollbarVertical);
+  put(ui->mScrollbarFaceColor);
+  put(ui->mScrollbarTrackColor);
   return list.forget();
 }
 

layout/style/nsComputedDOMStyle.h

@@ -459,9 +459,6 @@ private:
   void SetToRGBAColor(nsROCSSPrimitiveValue* aValue, nscolor aColor);
   void SetValueFromComplexColor(nsROCSSPrimitiveValue* aValue,
                                 const mozilla::StyleComplexColor& aColor);
-  void SetValueForWidgetColor(nsROCSSPrimitiveValue* aValue,
-                              const mozilla::StyleComplexColor& aColor,
-                              mozilla::StyleAppearance aWidgetType);
   void SetValueToPositionCoord(const mozilla::Position::Coord& aCoord,
                                nsROCSSPrimitiveValue* aValue);
   void SetValueToPosition(const mozilla::Position& aPosition,

layout/style/test/test_transitions_per_property.html

@@ -1590,9 +1590,14 @@ function test_auto_color_transition(prop, options={}) {
   const test_color = "rgb(51, 102, 153)";
   div.style.setProperty("transition-property", "none", "");
   div.style.setProperty(prop, "auto", "");
-  let used_value_of_auto = get_color(cs.getPropertyValue(prop));
-  isnot(used_value_of_auto, test_color,
-        msg_prefix + "ensure used auto value is different than our test color");
+  if (prop == "scrollbar-color") {
+    is(cs.getPropertyValue(prop), "auto",
+       msg_prefix + "auto should not be resolved to rgb color");
+  } else {
+    let used_value_of_auto = get_color(cs.getPropertyValue(prop));
+    isnot(used_value_of_auto, test_color,
+          msg_prefix + "ensure used auto value is different than our test color");
+  }
 
   div.style.setProperty("transition-property", prop, "");
   div.style.setProperty(prop, set_color(test_color), "");

widget/cocoa/nsNativeThemeCocoa.h

@@ -380,8 +380,6 @@ public:
                                   WidgetType aWidgetType,
                                   const nsRect& aRect,
                                   const nsRect& aDirtyRect) override;
-  nscolor GetWidgetAutoColor(mozilla::ComputedStyle* aStyle,
-                             WidgetType aWidgetType) override;
   bool CreateWebRenderCommandsForWidget(mozilla::wr::DisplayListBuilder& aBuilder,
                                         mozilla::wr::IpcResourceUpdateQueue& aResources,
                                         const mozilla::layers::StackingContextHelper& aSc,

widget/cocoa/nsNativeThemeCocoa.mm

@@ -3994,31 +3994,6 @@ nsNativeThemeCocoa::CreateWebRenderCommandsForWidget(mozilla::wr::DisplayListBui
   }
 }
 
-
-nscolor
-nsNativeThemeCocoa::GetWidgetAutoColor(mozilla::ComputedStyle* aStyle,
-                                       WidgetType aWidgetType)
-{
-  switch (aWidgetType) {
-    case StyleAppearance::Scrollbar:
-    case StyleAppearance::ScrollbarSmall:
-    case StyleAppearance::ScrollbarVertical:
-    case StyleAppearance::ScrollbarHorizontal:
-    case StyleAppearance::ScrollbarbuttonUp:
-    case StyleAppearance::ScrollbarbuttonDown:
-    case StyleAppearance::ScrollbarbuttonLeft:
-    case StyleAppearance::ScrollbarbuttonRight:
-      return NS_RGB(0xFA, 0xFA, 0xFA);
-
-    case StyleAppearance::ScrollbarthumbVertical:
-    case StyleAppearance::ScrollbarthumbHorizontal:
-      return NS_RGB(0xC1, 0xC1, 0xC1);
-
-    default:
-      return nsITheme::GetWidgetAutoColor(aStyle, aWidgetType);
-  }
-}
-
 LayoutDeviceIntMargin
 nsNativeThemeCocoa::DirectionAwareMargin(const LayoutDeviceIntMargin& aMargin,
                                          nsIFrame* aFrame)

widget/windows/nsNativeThemeWin.cpp

@@ -1989,41 +1989,6 @@ RENDER_AGAIN:
   return NS_OK;
 }
 
-static nscolor
-GetScrollbarFaceColorForAuto(ComputedStyle* aStyle)
-{
-  return NS_RGB(205, 205, 205);
-}
-
-static nscolor
-GetScrollbarTrackColorForAuto(ComputedStyle* aStyle)
-{
-  return NS_RGB(240, 240, 240);
-}
-
-nscolor
-nsNativeThemeWin::GetWidgetAutoColor(ComputedStyle* aStyle, WidgetType aWidgetType)
-{
-  switch (aWidgetType) {
-    case StyleAppearance::Scrollbar:
-    case StyleAppearance::ScrollbarSmall:
-    case StyleAppearance::ScrollbarVertical:
-    case StyleAppearance::ScrollbarHorizontal:
-    case StyleAppearance::ScrollbarbuttonUp:
-    case StyleAppearance::ScrollbarbuttonDown:
-    case StyleAppearance::ScrollbarbuttonLeft:
-    case StyleAppearance::ScrollbarbuttonRight:
-      return GetScrollbarTrackColorForAuto(aStyle);
-
-    case StyleAppearance::ScrollbarthumbVertical:
-    case StyleAppearance::ScrollbarthumbHorizontal:
-      return GetScrollbarFaceColorForAuto(aStyle);
-
-    default:
-      return nsITheme::GetWidgetAutoColor(aStyle, aWidgetType);
-  }
-}
-
 static void
 ScaleForFrameDPI(LayoutDeviceIntMargin* aMargin, nsIFrame* aFrame)
 {
@@ -4350,7 +4315,7 @@ nsNativeThemeWin::DrawCustomScrollbarPart(gfxContext* aContext,
 
   const nsStyleUI* ui = aStyle->StyleUI();
   nscolor trackColor = ui->mScrollbarTrackColor.IsAuto()
-    ? GetScrollbarTrackColorForAuto(aStyle)
+    ? NS_RGB(240, 240, 240)
     : ui->mScrollbarTrackColor.CalcColor(aStyle);
   switch (aWidgetType) {
     case StyleAppearance::ScrollbarHorizontal:
@@ -4387,7 +4352,7 @@ nsNativeThemeWin::DrawCustomScrollbarPart(gfxContext* aContext,
     case StyleAppearance::ScrollbarthumbVertical:
     case StyleAppearance::ScrollbarthumbHorizontal: {
       nscolor faceColor = ui->mScrollbarFaceColor.IsAuto()
-        ? GetScrollbarFaceColorForAuto(aStyle)
+        ? NS_RGB(205, 205, 205)
         : ui->mScrollbarFaceColor.CalcColor(aStyle);
       faceColor = AdjustScrollbarFaceColor(faceColor, eventStates);
       ctx->SetColor(Color::FromABGR(faceColor));

widget/windows/nsNativeThemeWin.h

@@ -37,9 +37,6 @@ public:
                                   const nsRect& aRect,
                                   const nsRect& aDirtyRect) override;
 
-  nscolor GetWidgetAutoColor(mozilla::ComputedStyle* aStyle,
-                             WidgetType aWidgetType) override;
-
   MOZ_MUST_USE LayoutDeviceIntMargin GetWidgetBorder(nsDeviceContext* aContext,
                                                      nsIFrame* aFrame,
                                                      WidgetType aWidgetType) override;