--- a/gfx/layers/apz/src/InputBlockState.h
+++ b/gfx/layers/apz/src/InputBlockState.h
@@ -3,16 +3,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_layers_InputBlockState_h
 #define mozilla_layers_InputBlockState_h
 
 #include "InputData.h"                      // for MultiTouchInput
+#include "mozilla/RefCounted.h"             // for RefCounted
 #include "mozilla/RefPtr.h"                 // for RefPtr
 #include "mozilla/gfx/Matrix.h"             // for Matrix4x4
 #include "mozilla/layers/APZUtils.h"        // for TouchBehaviorFlags
 #include "mozilla/layers/AsyncDragMetrics.h"
 #include "mozilla/TimeStamp.h"              // for TimeStamp
 #include "nsTArray.h"                       // for nsTArray
 #include "TouchCounter.h"
 
@@ -29,19 +30,21 @@ class PanGestureBlockState;
 
 /**
  * A base class that stores state common to various input blocks.
  * Currently, it just stores the overscroll handoff chain.
  * Note that the InputBlockState constructor acquires the tree lock, so callers
  * from inside AsyncPanZoomController should ensure that the APZC lock is not
  * held.
  */
-class InputBlockState
+class InputBlockState : public RefCounted<InputBlockState>
 {
 public:
+  MOZ_DECLARE_REFCOUNTED_TYPENAME(InputBlockState)
+
   static const uint64_t NO_BLOCK_ID = 0;
 
   enum class TargetConfirmationState {
     eUnconfirmed,
     eTimedOut,
     eTimedOutAndMainThreadResponded,
     eConfirmed
   };

--- a/gfx/layers/apz/src/InputQueue.h
+++ b/gfx/layers/apz/src/InputQueue.h
@@ -6,17 +6,16 @@
 #ifndef mozilla_layers_InputQueue_h
 #define mozilla_layers_InputQueue_h
 
 #include "APZUtils.h"
 #include "DragTracker.h"
 #include "InputData.h"
 #include "mozilla/EventForwards.h"
 #include "mozilla/RefPtr.h"
-#include "mozilla/UniquePtr.h"
 #include "nsTArray.h"
 #include "TouchCounter.h"
 
 namespace mozilla {
 
 class InputData;
 class MultiTouchInput;
 class ScrollWheelInput;
@@ -179,17 +178,17 @@ private:
                                  CancelableBlockState* aBlock);
   void MainThreadTimeout(const uint64_t& aInputBlockId);
   void ProcessInputBlocks();
   void UpdateActiveApzc(const RefPtr<AsyncPanZoomController>& aNewActive);
 
 private:
   // The queue of input blocks that have not yet been fully processed.
   // This member must only be accessed on the controller/UI thread.
-  nsTArray<UniquePtr<CancelableBlockState>> mInputBlockQueue;
+  nsTArray<RefPtr<CancelableBlockState>> mInputBlockQueue;
 
   // The APZC to which the last event was delivered
   RefPtr<AsyncPanZoomController> mLastActiveApzc;
 
   // Track touches so we know when to clear mLastActiveApzc
   TouchCounter mTouchCounter;
 
   // Track mouse inputs so we know if we're in a drag or not