Bug 1738152 - Remove the aOutSourceOfOverscrollTransform parameter of APZCTreeManager::ComputeTransformForNode(). r=hiro

This parameter was only used by InternalHitTester.

Differential Revision: https://phabricator.services.mozilla.com/D129763

gfx/layers/apz/src/APZCTreeManager.cpp

@@ -3348,8 +3348,7 @@ SideBits APZCTreeManager::SidesStuckToRootContent(
 }
 
 LayerToParentLayerMatrix4x4 APZCTreeManager::ComputeTransformForNode(
-    const HitTestingTreeNode* aNode,
-    const AsyncPanZoomController** aOutSourceOfOverscrollTransform) const {
+    const HitTestingTreeNode* aNode) const {
   mTreeLock.AssertCurrentThreadIn();
   // The async transforms applied here for hit-testing purposes, are intended
   // to match the ones AsyncCompositionManager (or equivalent WebRender code)
@@ -3386,19 +3385,12 @@ LayerToParentLayerMatrix4x4 APZCTreeManager::ComputeTransformForNode(
         visualTransformIsInheritedFromAncestor
             ? AsyncTransformComponents{AsyncTransformComponent::eLayout}
             : LayoutAndVisual;
-    if (aOutSourceOfOverscrollTransform &&
-        components.contains(AsyncTransformComponent::eVisual)) {
-      *aOutSourceOfOverscrollTransform = apzc;
-    }
     return aNode->GetTransform() *
            CompleteAsyncTransform(apzc->GetCurrentAsyncTransformWithOverscroll(
                AsyncPanZoomController::eForHitTesting, components));
   } else if (aNode->GetAsyncZoomContainerId()) {
     if (AsyncPanZoomController* rootContent =
             FindRootContentApzcForLayersId(aNode->GetLayersId())) {
-      if (aOutSourceOfOverscrollTransform) {
-        *aOutSourceOfOverscrollTransform = rootContent;
-      }
       return aNode->GetTransform() *
              CompleteAsyncTransform(
                  rootContent->GetCurrentAsyncTransformWithOverscroll(

gfx/layers/apz/src/APZCTreeManager.h

@@ -693,14 +693,9 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
 
   // Returns the transform that converts from |aNode|'s coordinates to
   // the coordinates of |aNode|'s parent in the hit-testing tree.
-  // If the returned transform includes an overscroll transform,
-  // |aOutSourceOfOverscrollTransform| (if not nullptr) is populated
-  // with the APZC which is the source of that overscroll transform.
   // Requires the caller to hold mTreeLock.
   LayerToParentLayerMatrix4x4 ComputeTransformForNode(
-      const HitTestingTreeNode* aNode,
-      const AsyncPanZoomController** aOutSourceOfOverscrollTransform =
-          nullptr) const;
+      const HitTestingTreeNode* aNode) const;
 
   // Look up the GeckoContentController for the given layers id.
   static already_AddRefed<GeckoContentController> GetContentController(