1 files changed, 54 insertions, 16 deletions

diff --git a/dom/base/Element.cpp b/dom/base/Element.cpp
index 3760dc43f..5c3277e84 100644
--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -687,19 +687,23 @@ Element::GetScrollFrame(nsIFrame **aStyledFrame, bool aFlushLayout)
 }
 
 void
-Element::ScrollIntoView()
+Element::ScrollIntoView(const BooleanOrScrollIntoViewOptions& aObject)
 {
-  ScrollIntoView(ScrollIntoViewOptions());
-}
+  if (aObject.IsScrollIntoViewOptions()) {
+    return ScrollIntoView(aObject.GetAsScrollIntoViewOptions());
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(aObject.IsBoolean());
 
-void
-Element::ScrollIntoView(bool aTop)
-{
   ScrollIntoViewOptions options;
-  if (!aTop) {
+  if (aObject.GetAsBoolean()) {
+    options.mBlock = ScrollLogicalPosition::Start;
+    options.mInline = ScrollLogicalPosition::Nearest;
+  } else {
     options.mBlock = ScrollLogicalPosition::End;
+    options.mInline = ScrollLogicalPosition::Nearest;
   }
-  ScrollIntoView(options);
+  return ScrollIntoView(options);
 }
 
 void
@@ -716,9 +720,41 @@ Element::ScrollIntoView(const ScrollIntoViewOptions &aOptions)
     return;
   }
 
-  int16_t vpercent = (aOptions.mBlock == ScrollLogicalPosition::Start)
-                       ? nsIPresShell::SCROLL_TOP
-                       : nsIPresShell::SCROLL_BOTTOM;
+  int16_t vpercent = nsIPresShell::SCROLL_CENTER;
+  switch (aOptions.mBlock) {
+    case ScrollLogicalPosition::Start:
+      vpercent = nsIPresShell::SCROLL_TOP;
+      break;
+    case ScrollLogicalPosition::Center:
+      vpercent = nsIPresShell::SCROLL_CENTER;
+      break;
+    case ScrollLogicalPosition::End:
+      vpercent = nsIPresShell::SCROLL_BOTTOM;
+      break;
+    case ScrollLogicalPosition::Nearest:
+      vpercent = nsIPresShell::SCROLL_MINIMUM;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unexpected ScrollLogicalPosition value");
+  }
+
+  int16_t hpercent = nsIPresShell::SCROLL_CENTER;
+  switch (aOptions.mInline) {
+    case ScrollLogicalPosition::Start:
+      hpercent = nsIPresShell::SCROLL_LEFT;
+      break;
+    case ScrollLogicalPosition::Center:
+      hpercent = nsIPresShell::SCROLL_CENTER;
+      break;
+    case ScrollLogicalPosition::End:
+      hpercent = nsIPresShell::SCROLL_RIGHT;
+      break;
+    case ScrollLogicalPosition::Nearest:
+      hpercent = nsIPresShell::SCROLL_MINIMUM;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unexpected ScrollLogicalPosition value");
+  }
 
   uint32_t flags = nsIPresShell::SCROLL_OVERFLOW_HIDDEN;
   if (aOptions.mBehavior == ScrollBehavior::Smooth) {
@@ -731,7 +767,9 @@ Element::ScrollIntoView(const ScrollIntoViewOptions &aOptions)
                                    nsIPresShell::ScrollAxis(
                                      vpercent,
                                      nsIPresShell::SCROLL_ALWAYS),
-                                   nsIPresShell::ScrollAxis(),
+                                   nsIPresShell::ScrollAxis(
+                                     hpercent,
+                                     nsIPresShell::SCROLL_ALWAYS),
                                    flags);
 }
 
@@ -3947,7 +3985,7 @@ Element::ClearDataset()
   slots->mDataset = nullptr;
 }
 
-nsDataHashtable<nsPtrHashKey<DOMIntersectionObserver>, int32_t>*
+nsDataHashtable<nsRefPtrHashKey<DOMIntersectionObserver>, int32_t>*
 Element::RegisteredIntersectionObservers()
 {
   nsDOMSlots* slots = DOMSlots();
@@ -3962,7 +4000,7 @@ enum nsPreviousIntersectionThreshold {
 void
 Element::RegisterIntersectionObserver(DOMIntersectionObserver* aObserver)
 {
-  nsDataHashtable<nsPtrHashKey<DOMIntersectionObserver>, int32_t>* observers =
+  nsDataHashtable<nsRefPtrHashKey<DOMIntersectionObserver>, int32_t>* observers =
     RegisteredIntersectionObservers();
   if (observers->Contains(aObserver)) {
     return;
@@ -3979,7 +4017,7 @@ Element::RegisterIntersectionObserver(DOMIntersectionObserver* aObserver)
 void
 Element::UnregisterIntersectionObserver(DOMIntersectionObserver* aObserver)
 {
-  nsDataHashtable<nsPtrHashKey<DOMIntersectionObserver>, int32_t>* observers =
+  nsDataHashtable<nsRefPtrHashKey<DOMIntersectionObserver>, int32_t>* observers =
     RegisteredIntersectionObservers();
   observers->Remove(aObserver);
 }
@@ -3987,7 +4025,7 @@ Element::UnregisterIntersectionObserver(DOMIntersectionObserver* aObserver)
 bool
 Element::UpdateIntersectionObservation(DOMIntersectionObserver* aObserver, int32_t aThreshold)
 {
-  nsDataHashtable<nsPtrHashKey<DOMIntersectionObserver>, int32_t>* observers =
+  nsDataHashtable<nsRefPtrHashKey<DOMIntersectionObserver>, int32_t>* observers =
     RegisteredIntersectionObservers();
   if (!observers->Contains(aObserver)) {
     return false;