Bug 1420026 - Part 1: Add aWasCurrentColor outparam to ServoCSSParser::ComputeColor. r=TYLin

MozReview-Commit-ID: CMv0LedpEfv

--HG--
extra : rebase_source : 98a491d4a9a9b14d7364501138ca83cd9ec5821c

layout/style/ServoBindingList.h

@@ -744,7 +744,8 @@ SERVO_BINDING_FUNC(Servo_ComputeColor, bool,
                    RawServoStyleSetBorrowedOrNull set,
                    nscolor current_color,
                    const nsAString* value,
-                   nscolor* result_color);
+                   nscolor* result_color,
+                   bool* was_current_color);
 SERVO_BINDING_FUNC(Servo_ParseIntersectionObserverRootMargin, bool,
                    const nsAString* value,
                    nsCSSRect* result);

layout/style/ServoCSSParser.cpp

@@ -20,10 +20,12 @@ ServoCSSParser::IsValidCSSColor(const nsAString& aValue)
 ServoCSSParser::ComputeColor(ServoStyleSet* aStyleSet,
                              nscolor aCurrentColor,
                              const nsAString& aValue,
-                             nscolor* aResultColor)
+                             nscolor* aResultColor,
+                             bool* aWasCurrentColor)
 {
   return Servo_ComputeColor(aStyleSet ? aStyleSet->RawSet() : nullptr,
-                            aCurrentColor, &aValue, aResultColor);
+                            aCurrentColor, &aValue, aResultColor,
+                            aWasCurrentColor);
 }
 
 /* static */ bool

layout/style/ServoCSSParser.h

@@ -32,12 +32,15 @@ public:
    * @param aCurrentColor The color value that currentcolor should compute to.
    * @param aValue The CSS <color> value.
    * @param aResultColor The resulting computed color value.
+   * @param aWasCurrentColor Whether aValue was currentcolor. Can be nullptr
+   *   if the caller doesn't care.
    * @return Whether aValue was successfully parsed and aResultColor was set.
    */
   static bool ComputeColor(ServoStyleSet* aStyleSet,
                            nscolor aCurrentColor,
                            const nsAString& aValue,
-                           nscolor* aResultColor);
+                           nscolor* aResultColor,
+                           bool* aWasCurrentColor = nullptr);
 
   /**
    * Parses a IntersectionObserver's initialization dictionary's rootMargin