Bug 1691355. Check in a few places for a zero margin display port and set a full one. r=botond

Differential Revision: https://phabricator.services.mozilla.com/D104361

gfx/layers/apz/util/APZCCallbackHelper.cpp

@@ -619,7 +619,7 @@ static bool PrepareForSetTargetAPZCNotification(
   if (!guidIsValid) {
     return false;
   }
-  if (DisplayPortUtils::HasNonMinimalDisplayPort(dpElement)) {
+  if (DisplayPortUtils::HasNonMinimalNonZeroDisplayPort(dpElement)) {
     // If the element has a displayport but it hasn't been painted yet,
     // we want the caller to wait for the paint to happen, but we don't
     // need to set the displayport here since it's already been set.

layout/generic/nsGfxScrollFrame.cpp

@@ -4720,7 +4720,7 @@ void ScrollFrameHelper::ScrollBy(nsIntPoint aDelta, ScrollUnit aUnit,
         ScrollPositionUpdate::NewPureRelativeScroll(aOrigin, aMode, delta));
 
     nsIContent* content = mOuter->GetContent();
-    if (!DisplayPortUtils::HasNonMinimalDisplayPort(content)) {
+    if (!DisplayPortUtils::HasNonMinimalNonZeroDisplayPort(content)) {
       if (MOZ_LOG_TEST(sDisplayportLog, LogLevel::Debug)) {
         mozilla::layers::ScrollableLayerGuid::ViewID viewID =
             mozilla::layers::ScrollableLayerGuid::NULL_SCROLL_ID;
@@ -7829,7 +7829,7 @@ void ScrollFrameHelper::ApzSmoothScrollTo(const nsPoint& aDestination,
       ScrollPositionUpdate::NewSmoothScroll(aOrigin, aDestination));
 
   nsIContent* content = mOuter->GetContent();
-  if (!DisplayPortUtils::HasNonMinimalDisplayPort(content)) {
+  if (!DisplayPortUtils::HasNonMinimalNonZeroDisplayPort(content)) {
     // If this frame doesn't have a displayport then there won't be an
     // APZC instance for it and so there won't be anything to process
     // this smooth scroll request. We should set a displayport on this