--- a/layout/base/AccessibleCaretManager.cpp
+++ b/layout/base/AccessibleCaretManager.cpp
@@ -505,17 +505,21 @@ AccessibleCaretManager::DragCaret(const 
 {
   MOZ_ASSERT(mActiveCaret);
   MOZ_ASSERT(GetCaretMode() != CaretMode::None);
 
   if (!mPresShell || !mPresShell->GetRootFrame() || !GetSelection()) {
     return NS_ERROR_NULL_POINTER;
   }
 
+  StopSelectionAutoScrollTimer();
   DragCaretInternal(aPoint);
+
+  // We want to scroll the page even if we failed to drag the caret.
+  StartSelectionAutoScrollTimer(aPoint);
   UpdateCarets();
   return NS_OK;
 }
 
 nsresult
 AccessibleCaretManager::ReleaseCaret()
 {
   MOZ_ASSERT(mActiveCaret);
@@ -1248,45 +1252,26 @@ AccessibleCaretManager::DragCaretInterna
   }
 
   nsIFrame::ContentOffsets offsets =
     newFrame->GetContentOffsetsFromPoint(newPoint);
   if (offsets.IsNull()) {
     return NS_ERROR_FAILURE;
   }
 
-  Selection* selection = GetSelection();
-  MOZ_ASSERT(selection);
-
   if (GetCaretMode() == CaretMode::Selection &&
       !RestrictCaretDraggingOffsets(offsets)) {
     return NS_ERROR_FAILURE;
   }
 
   ClearMaintainedSelection();
 
-  nsIFrame* anchorFrame = nullptr;
-  selection->GetPrimaryFrameForAnchorNode(&anchorFrame);
-
-  nsIFrame* scrollable =
-    nsLayoutUtils::GetClosestFrameOfType(anchorFrame, LayoutFrameType::Scroll);
-  AutoWeakFrame weakScrollable = scrollable;
   fs->HandleClick(offsets.content, offsets.StartOffset(), offsets.EndOffset(),
                   GetCaretMode() == CaretMode::Selection, false,
                   offsets.associate);
-  if (!weakScrollable.IsAlive()) {
-    return NS_OK;
-  }
-
-  // Scroll scrolled frame.
-  nsIScrollableFrame* saf = do_QueryFrame(scrollable);
-  nsIFrame* capturingFrame = saf->GetScrolledFrame();
-  nsPoint ptInScrolled = point;
-  nsLayoutUtils::TransformPoint(rootFrame, capturingFrame, ptInScrolled);
-  fs->StartAutoScrollTimer(capturingFrame, ptInScrolled, kAutoScrollTimerDelay);
   return NS_OK;
 }
 
 nsRect
 AccessibleCaretManager::GetAllChildFrameRectsUnion(nsIFrame* aFrame) const
 {
   nsRect unionRect;
 
@@ -1371,16 +1356,61 @@ AccessibleCaretManager::AdjustDragBounda
       }
     }
   }
 
   return adjustedPoint;
 }
 
 void
+AccessibleCaretManager::StartSelectionAutoScrollTimer(
+  const nsPoint& aPoint) const
+{
+  Selection* selection = GetSelection();
+  MOZ_ASSERT(selection);
+
+  nsIFrame* anchorFrame = nullptr;
+  selection->GetPrimaryFrameForAnchorNode(&anchorFrame);
+  if (!anchorFrame) {
+    return;
+  }
+
+  nsIScrollableFrame* scrollFrame =
+    nsLayoutUtils::GetNearestScrollableFrame(
+      anchorFrame,
+      nsLayoutUtils::SCROLLABLE_SAME_DOC |
+      nsLayoutUtils::SCROLLABLE_INCLUDE_HIDDEN);
+  if (!scrollFrame) {
+    return;
+  }
+
+  nsIFrame* capturingFrame = scrollFrame->GetScrolledFrame();
+  if (!capturingFrame) {
+    return;
+  }
+
+  nsIFrame* rootFrame = mPresShell->GetRootFrame();
+  MOZ_ASSERT(rootFrame);
+  nsPoint ptInScrolled = aPoint;
+  nsLayoutUtils::TransformPoint(rootFrame, capturingFrame, ptInScrolled);
+
+  RefPtr<nsFrameSelection> fs = GetFrameSelection();
+  MOZ_ASSERT(fs);
+  fs->StartAutoScrollTimer(capturingFrame, ptInScrolled, kAutoScrollTimerDelay);
+}
+
+void
+AccessibleCaretManager::StopSelectionAutoScrollTimer() const
+{
+  RefPtr<nsFrameSelection> fs = GetFrameSelection();
+  MOZ_ASSERT(fs);
+  fs->StopAutoScrollTimer();
+}
+
+void
 AccessibleCaretManager::DispatchCaretStateChangedEvent(CaretChangedReason aReason) const
 {
   if (!mPresShell) {
     return;
   }
 
   FlushLayout();
   if (IsTerminated()) {

--- a/layout/base/AccessibleCaretManager.h
+++ b/layout/base/AccessibleCaretManager.h
@@ -186,16 +186,22 @@ protected:
   nsIFrame* GetFrameForFirstRangeStartOrLastRangeEnd(
     nsDirection aDirection,
     int32_t* aOutOffset,
     nsIContent** aOutContent = nullptr,
     int32_t* aOutContentOffset = nullptr) const;
 
   nsresult DragCaretInternal(const nsPoint& aPoint);
   nsPoint AdjustDragBoundary(const nsPoint& aPoint) const;
+
+  // Start the selection scroll timer if the caret is being dragged out of
+  // the scroll port.
+  void StartSelectionAutoScrollTimer(const nsPoint& aPoint) const;
+  void StopSelectionAutoScrollTimer() const;
+
   void ClearMaintainedSelection() const;
 
   // Caller is responsible to use IsTerminated() to check whether PresShell is
   // still valid.
   void FlushLayout() const;
 
   dom::Element* GetEditingHostForFrame(nsIFrame* aFrame) const;
   dom::Selection* GetSelection() const;