Bug 1751967 - Remove dom.event.wheelDelta.enabled. r=webidl,peterv

We shipped it as true successfully for a long while (since version 90).

Differential Revision: https://phabricator.services.mozilla.com/D136917

dom/events/test/test_dom_wheel_event.html

@@ -820,7 +820,6 @@ function runTest()
     ["layout.css.devPixelsPerPx", 1.0],
 
     ["dom.event.wheel-deltaMode-lines.disabled", true],
-    ["dom.event.wheelDelta.enabled", true],
 
     ["mousewheel.default.delta_multiplier_x", 100],
     ["mousewheel.default.delta_multiplier_y", 100],

dom/webidl/WheelEvent.webidl

@@ -20,11 +20,11 @@ interface WheelEvent : MouseEvent
   const unsigned long DOM_DELTA_PAGE  = 0x02;
 
   // Legacy MouseWheelEvent API replaced by standard WheelEvent API.
-  [Pref="dom.event.wheelDelta.enabled", NeedsCallerType]
+  [NeedsCallerType]
   readonly attribute long wheelDeltaX;
-  [Pref="dom.event.wheelDelta.enabled", NeedsCallerType]
+  [NeedsCallerType]
   readonly attribute long wheelDeltaY;
-  [Pref="dom.event.wheelDelta.enabled", NeedsCallerType]
+  [NeedsCallerType]
   readonly attribute long wheelDelta;
 
   [NeedsCallerType] readonly attribute double        deltaX;

modules/libpref/init/StaticPrefList.yaml

@@ -2145,12 +2145,6 @@
   value: ""
   mirror: never
 
-# Whether WheelEvent should expose wheelDelta / wheelDeltaX / wheelDeltaY
-- name: dom.event.wheelDelta.enabled
-  type: bool
-  value: true
-  mirror: always
-
 #if defined(XP_MACOSX)
 # Whether to disable treating ctrl click as right click
 - name: dom.event.treat_ctrl_click_as_right_click.disabled