Bug 1643042 - Switch mLastSmoothScrollOrigin to using None as well. r=tnikkel

This uses "None" instead of "NotSpecified" as the value for
mLastSmoothScrollOrigin when there is no smooth scroll in progress.

Depends on D78439

Differential Revision: https://phabricator.services.mozilla.com/D78469

gfx/layers/apz/util/APZCCallbackHelper.cpp

@@ -818,7 +818,7 @@ void APZCCallbackHelper::NotifyFlushComplete(PresShell* aPresShell) {
 bool APZCCallbackHelper::IsScrollInProgress(nsIScrollableFrame* aFrame) {
   return aFrame->IsProcessingAsyncScroll() ||
          nsLayoutUtils::CanScrollOriginClobberApz(aFrame->LastScrollOrigin()) ||
-         aFrame->LastSmoothScrollOrigin() != ScrollOrigin::NotSpecified;
+         aFrame->LastSmoothScrollOrigin() != ScrollOrigin::None;
 }
 
 /* static */

layout/base/nsLayoutUtils.cpp

@@ -9185,7 +9185,7 @@ ScrollMetadata nsLayoutUtils::ComputeScrollMetadata(
 
     ScrollOrigin lastSmoothScrollOrigin =
         scrollableFrame->LastSmoothScrollOrigin();
-    if (lastSmoothScrollOrigin != ScrollOrigin::NotSpecified) {
+    if (lastSmoothScrollOrigin != ScrollOrigin::None) {
       metrics.SetSmoothScrollOffsetUpdated(
           scrollableFrame->CurrentScrollGeneration());
     }

layout/generic/ScrollOrigin.h

@@ -13,13 +13,13 @@ namespace mozilla {
 enum class ScrollOrigin : uint8_t {
   // This is used as an initial value for the "LastScrollOrigin" property on
   // scrollable frames. It is not intended to be an actual scroll origin, but
-  // a sentinel value that indicates that there was no "last scroll".
+  // a sentinel value that indicates that there was no "last scroll". It is
+  // used similarly for the "LastSmoothScrollOrigin" property, to indicate
+  // no smooth scroll is in progress.
   None,
 
   // This is a default value that we use when we don't know of a more specific
-  // value that we can use. Note that for the "LastSmoothScrollOrigin" property
-  // on a scrollable frame, the NotSpecified value is special, in that it means
-  // there is no smooth scroll in progress.
+  // value that we can use.
   NotSpecified,
   // The scroll came from APZ code.
   Apz,

layout/generic/nsGfxScrollFrame.cpp

@@ -2090,7 +2090,7 @@ ScrollFrameHelper::ScrollFrameHelper(nsContainerFrame* aOuter, bool aIsRoot)
       mAsyncScroll(nullptr),
       mAsyncSmoothMSDScroll(nullptr),
       mLastScrollOrigin(ScrollOrigin::None),
-      mLastSmoothScrollOrigin(ScrollOrigin::NotSpecified),
+      mLastSmoothScrollOrigin(ScrollOrigin::None),
       mScrollGeneration(++sScrollGenerationCounter),
       mDestination(0, 0),
       mRestorePos(-1, -1),
@@ -2893,7 +2893,7 @@ void ScrollFrameHelper::ScrollToImpl(nsPoint aPt, const nsRect& aRange,
     mLastScrollOrigin = aOrigin;
     mAllowScrollOriginDowngrade = false;
   }
-  mLastSmoothScrollOrigin = ScrollOrigin::NotSpecified;
+  mLastSmoothScrollOrigin = ScrollOrigin::None;
   mScrollGeneration = ++sScrollGenerationCounter;
   if (mLastScrollOrigin == ScrollOrigin::Apz) {
     mApzScrollPos = GetScrollPosition();
@@ -6655,7 +6655,7 @@ UniquePtr<PresState> ScrollFrameHelper::SaveState() const {
   // Don't store a scroll state if we never have been scrolled or restored
   // a previous scroll state, and we're not in the middle of a smooth scroll.
   bool isInSmoothScroll = IsProcessingAsyncScroll() ||
-                          mLastSmoothScrollOrigin != ScrollOrigin::NotSpecified;
+                          mLastSmoothScrollOrigin != ScrollOrigin::None;
   if (!mHasBeenScrolled && !mDidHistoryRestore && !isInSmoothScroll) {
     return nullptr;
   }
@@ -7244,7 +7244,7 @@ void ScrollFrameHelper::ApzSmoothScrollTo(const nsPoint& aDestination,
   // The animation will be handled in the compositor, pass the
   // information needed to start the animation and skip the main-thread
   // animation for this scroll.
-  MOZ_ASSERT(aOrigin != ScrollOrigin::NotSpecified);
+  MOZ_ASSERT(aOrigin != ScrollOrigin::None);
   mLastSmoothScrollOrigin = aOrigin;
   mApzSmoothScrollDestination = Some(aDestination);
   mScrollGeneration = ++sScrollGenerationCounter;

layout/generic/nsGfxScrollFrame.h

@@ -467,7 +467,7 @@ class ScrollFrameHelper : public nsIReflowCallback {
   void ResetScrollInfoIfGeneration(uint32_t aGeneration) {
     if (aGeneration == mScrollGeneration) {
       mLastScrollOrigin = ScrollOrigin::NotSpecified;
-      mLastSmoothScrollOrigin = ScrollOrigin::NotSpecified;
+      mLastSmoothScrollOrigin = ScrollOrigin::None;
     }
   }
   bool WantAsyncScroll() const;