Unprefix ::-moz-selection.

devtools/client/inspector/rules/test/browser_rules_pseudo-element_01.js

@@ -29,7 +29,7 @@ function* testTopLeft(inspector, view) {
       elementRulesNb: 4,
       firstLineRulesNb: 2,
       firstLetterRulesNb: 1,
-      selectionRulesNb: 0,
+      selectionRulesNb: 1,
       afterRulesNb: 1,
       beforeRulesNb: 2
     }
@@ -166,7 +166,7 @@ function* testParagraph(inspector, view) {
       elementRulesNb: 3,
       firstLineRulesNb: 1,
       firstLetterRulesNb: 1,
-      selectionRulesNb: 1,
+      selectionRulesNb: 2,
       beforeRulesNb: 0,
       afterRulesNb: 0
     });
@@ -216,7 +216,7 @@ function* assertPseudoElementRulesNumbers(selector, inspector, view, ruleNbs) {
     firstLetterRules: elementStyle.rules.filter(rule =>
       rule.pseudoElement === ":first-letter"),
     selectionRules: elementStyle.rules.filter(rule =>
-      rule.pseudoElement === ":-moz-selection"),
+      rule.pseudoElement === ":selection"),
     beforeRules: elementStyle.rules.filter(rule =>
       rule.pseudoElement === ":before"),
     afterRules: elementStyle.rules.filter(rule =>

devtools/shared/css/generated/properties-db.js

@@ -9398,6 +9398,7 @@ exports.PSEUDO_ELEMENTS = [
   ":backdrop",
   ":first-letter",
   ":first-line",
+  ":selection",
   ":-moz-selection",
   ":-moz-focus-inner",
   ":-moz-focus-outer",

layout/generic/nsTextFrame.cpp

@@ -3947,11 +3947,18 @@ nsTextPaintStyle::InitSelectionColorsAndShadow()
   if (selectionElement &&
       selectionStatus == nsISelectionController::SELECTION_ON) {
     RefPtr<nsStyleContext> sc = nullptr;
+    // Probe for both selection and -moz-selection
     sc = mPresContext->StyleSet()->
       ProbePseudoElementStyle(selectionElement,
-                              CSSPseudoElementType::mozSelection,
+                              CSSPseudoElementType::selection,
                               mFrame->StyleContext());
-    // Use -moz-selection pseudo class.
+    if (!sc) {
+      sc = mPresContext->StyleSet()->
+        ProbePseudoElementStyle(selectionElement,
+                                CSSPseudoElementType::mozSelection,
+                                mFrame->StyleContext());
+    }
+    // Use selection pseudo class.
     if (sc) {
       mSelectionBGColor =
         sc->GetVisitedDependentColor(eCSSProperty_background_color);

layout/inspector/tests/test_getCSSPseudoElementNames.html

@@ -16,6 +16,7 @@
     ":first-letter",
     ":first-line",
     ":placeholder",
+    ":selection",
     ":-moz-color-swatch",
     ":-moz-focus-inner",
     ":-moz-focus-outer",

layout/style/nsCSSPseudoElementList.h

@@ -37,6 +37,9 @@ CSS_PSEUDO_ELEMENT(firstLine, ":first-line",
                    CSS_PSEUDO_ELEMENT_IS_CSS2 |
                    CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS)
 
+CSS_PSEUDO_ELEMENT(selection, ":selection",
+                   CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS)
+// Keep the prefixed version for now.
 CSS_PSEUDO_ELEMENT(mozSelection, ":-moz-selection",
                    CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS)