--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -49,16 +49,17 @@
 #include "mozilla/layers/APZCTreeManager.h"  // for ScrollableLayerGuid
 #include "mozilla/layers/APZThreadUtils.h"  // for AssertOnControllerThread, etc
 #include "mozilla/layers/AsyncCompositionManager.h"  // for ViewTransform
 #include "mozilla/layers/AxisPhysicsModel.h" // for AxisPhysicsModel
 #include "mozilla/layers/AxisPhysicsMSDModel.h" // for AxisPhysicsMSDModel
 #include "mozilla/layers/CompositorParent.h" // for CompositorParent
 #include "mozilla/layers/LayerTransactionParent.h" // for LayerTransactionParent
 #include "mozilla/layers/PCompositorParent.h" // for PCompositorParent
+#include "mozilla/layers/ScrollInputMethods.h" // for ScrollInputMethod
 #include "mozilla/mozalloc.h"           // for operator new, etc
 #include "mozilla/unused.h"             // for unused
 #include "mozilla/FloatingPoint.h"      // for FuzzyEquals*
 #include "nsAlgorithm.h"                // for clamped
 #include "nsAutoPtr.h"                  // for nsRefPtr
 #include "nsCOMPtr.h"                   // for already_AddRefed
 #include "nsDebug.h"                    // for NS_WARNING
 #include "nsIDOMWindowUtils.h"          // for nsIDOMWindowUtils
@@ -1030,16 +1031,19 @@ nsEventStatus AsyncPanZoomController::Ha
   }
 
   RefPtr<HitTestingTreeNode> node =
     GetApzcTreeManager()->FindScrollNode(aDragMetrics);
   if (!node) {
     return nsEventStatus_eConsumeNoDefault;
   }
 
+  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
+      (uint32_t) ScrollInputMethod::ApzScrollbarDrag);
+
   ReentrantMonitorAutoEnter lock(mMonitor);
   CSSPoint scrollFramePoint = aEvent.mLocalOrigin / GetFrameMetrics().GetZoom();
   // The scrollbar can be transformed with the frame but the pres shell
   // resolution is only applied to the scroll frame.
   CSSPoint scrollbarPoint = scrollFramePoint * mFrameMetrics.GetPresShellResolution();
   CSSRect cssCompositionBound = mFrameMetrics.CalculateCompositedRectInCssPixels();
 
   float mousePosition = GetAxisStart(aDragMetrics.mDirection, scrollbarPoint) -
@@ -1727,16 +1731,35 @@ AsyncPanZoomController::AllowScrollHando
       if (currentBlock->GetScrolledApzc() == this) {
         result = false;
       }
     }
   }
   return result;
 }
 
+static ScrollInputMethod
+ScrollInputMethodForWheelDeltaType(ScrollWheelInput::ScrollDeltaType aDeltaType)
+{
+  switch (aDeltaType) {
+    case ScrollWheelInput::SCROLLDELTA_LINE: {
+      return ScrollInputMethod::ApzWheelLine;
+    }
+    case ScrollWheelInput::SCROLLDELTA_PAGE: {
+      return ScrollInputMethod::ApzWheelPage;
+    }
+    case ScrollWheelInput::SCROLLDELTA_PIXEL: {
+      return ScrollInputMethod::ApzWheelPixel;
+    }
+    default:
+      MOZ_ASSERT_UNREACHABLE("unexpected scroll delta type");
+      return ScrollInputMethod::ApzWheelLine;
+  }
+}
+
 nsEventStatus AsyncPanZoomController::OnScrollWheel(const ScrollWheelInput& aEvent)
 {
   ParentLayerPoint delta = GetScrollWheelDelta(aEvent);
   APZC_LOG("%p got a scroll-wheel with delta %s\n", this, Stringify(delta).c_str());
 
   if ((delta.x || delta.y) && !CanScrollWithWheel(delta)) {
     // We can't scroll this apz anymore, so we simply drop the event.
     if (mInputQueue->GetCurrentWheelTransaction() &&
@@ -1750,16 +1773,19 @@ nsEventStatus AsyncPanZoomController::On
     return nsEventStatus_eConsumeNoDefault;
   }
 
   if (delta.x == 0 && delta.y == 0) {
     // Avoid spurious state changes and unnecessary work
     return nsEventStatus_eIgnore;
   }
 
+  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
+      (uint32_t) ScrollInputMethodForWheelDeltaType(aEvent.mDeltaType));
+
   switch (aEvent.mScrollMode) {
     case ScrollWheelInput::SCROLLMODE_INSTANT: {
       ScreenPoint distance = ToScreenCoordinates(
         ParentLayerPoint(fabs(delta.x), fabs(delta.y)), aEvent.mLocalOrigin);
 
       CancelAnimation();
 
       OverscrollHandoffState handoffState(
@@ -1908,16 +1934,19 @@ nsEventStatus AsyncPanZoomController::On
   // size and position. We need to do so even if this is a momentum pan (i.e.
   // aFingersOnTouchpad == false); in that case the "with touch" part is not
   // really appropriate, so we may want to rethink this at some point.
   mX.UpdateWithTouchAtDevicePoint(aEvent.mLocalPanStartPoint.x, aEvent.mLocalPanDisplacement.x, aEvent.mTime);
   mY.UpdateWithTouchAtDevicePoint(aEvent.mLocalPanStartPoint.y, aEvent.mLocalPanDisplacement.y, aEvent.mTime);
 
   HandlePanningUpdate(aEvent.mPanDisplacement);
 
+  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
+      (uint32_t) ScrollInputMethod::ApzPanGesture);
+
   ScreenPoint panDistance(fabs(aEvent.mPanDisplacement.x), fabs(aEvent.mPanDisplacement.y));
   OverscrollHandoffState handoffState(
       *CurrentPanGestureBlock()->GetOverscrollHandoffChain(),
       panDistance,
       ScrollSource::Wheel);
 
   // Create fake "touch" positions that will result in the desired scroll motion.
   // Note that the pan displacement describes the change in scroll position:
@@ -2566,16 +2595,18 @@ void AsyncPanZoomController::TrackTouch(
       ParentLayerPoint(mX.PanDistance(touchPoint.x),
                        mY.PanDistance(touchPoint.y)),
       PanStart());
   HandlePanningUpdate(panDistance);
 
   UpdateWithTouchAtDevicePoint(aEvent);
 
   if (prevTouchPoint != touchPoint) {
+    mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
+        (uint32_t) ScrollInputMethod::ApzTouch);
     OverscrollHandoffState handoffState(
         *CurrentTouchBlock()->GetOverscrollHandoffChain(),
         panDistance,
         ScrollSource::Touch);
     CallDispatchScroll(prevTouchPoint, touchPoint, handoffState);
   }
 }