--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -267,17 +267,17 @@ APZCTreeManager::APZCTreeManager(LayersI
       mApzcTreeLog("apzctree"),
       mTestDataLock("APZTestDataLock"),
       mDPI(160.0) {
   RefPtr<APZCTreeManager> self(this);
   NS_DispatchToMainThread(NS_NewRunnableFunction(
       "layers::APZCTreeManager::APZCTreeManager",
       [self] { self->mFlushObserver = new CheckerboardFlushObserver(self); }));
   AsyncPanZoomController::InitializeGlobalState();
-  mApzcTreeLog.ConditionOnPrefFunction(StaticPrefs::APZPrintTree);
+  mApzcTreeLog.ConditionOnPrefFunction(StaticPrefs::apz_printtree);
 #if defined(MOZ_WIDGET_ANDROID)
   if (jni::IsFennec()) {
     mToolbarAnimator = new AndroidDynamicToolbarAnimator(this);
   }
 #endif  // (MOZ_WIDGET_ANDROID)
 }
 
 APZCTreeManager::~APZCTreeManager() = default;
@@ -601,17 +601,17 @@ APZCTreeManager::UpdateHitTestingTreeImp
   SendSubtreeTransformsToChromeMainThread(nullptr);
 }
 
 void APZCTreeManager::UpdateFocusState(LayersId aRootLayerTreeId,
                                        LayersId aOriginatingLayersId,
                                        const FocusTarget& aFocusTarget) {
   AssertOnUpdaterThread();
 
-  if (!StaticPrefs::APZKeyboardEnabled()) {
+  if (!StaticPrefs::apz_keyboard_enabled()) {
     return;
   }
 
   mFocusState.Update(aRootLayerTreeId, aOriginatingLayersId, aFocusTarget);
 }
 
 void APZCTreeManager::UpdateHitTestingTree(Layer* aRoot, bool aIsFirstPaint,
                                            LayersId aOriginatingLayersId,
@@ -1314,17 +1314,17 @@ nsEventStatus APZCTreeManager::ReceiveIn
           MutexAutoLock lock(mTestDataLock);
           auto it = mTestData.find(guid.mLayersId);
           MOZ_ASSERT(it != mTestData.end());
           it->second->RecordHitResult(mouseInput.mOrigin, hitResult,
                                       guid.mScrollId);
         }
 
         TargetConfirmationFlags confFlags{hitResult};
-        bool apzDragEnabled = StaticPrefs::APZDragEnabled();
+        bool apzDragEnabled = StaticPrefs::apz_drag_enabled();
         if (apzDragEnabled && hitScrollbar) {
           // If scrollbar dragging is enabled and we hit a scrollbar, wait
           // for the main-thread confirmation because it contains drag metrics
           // that we need.
           confFlags.mTargetConfirmed = false;
         }
         result = mInputQueue->ReceiveInputEvent(apzc, confFlags, mouseInput,
                                                 aOutInputBlockId);
@@ -1539,18 +1539,18 @@ nsEventStatus APZCTreeManager::ReceiveIn
         apzc->GetGuid(aOutTargetGuid);
         tapInput.mPoint = *untransformedPoint;
       }
       break;
     }
     case KEYBOARD_INPUT: {
       // Disable async keyboard scrolling when accessibility.browsewithcaret is
       // enabled
-      if (!StaticPrefs::APZKeyboardEnabled() ||
-          StaticPrefs::AccessibilityBrowseWithCaret()) {
+      if (!StaticPrefs::apz_keyboard_enabled() ||
+          StaticPrefs::accessibility_browsewithcaret()) {
         APZ_KEY_LOG("Skipping key input from invalid prefs\n");
         return result;
       }
 
       KeyboardInput& keyInput = aEvent.AsKeyboardInput();
 
       // Try and find a matching shortcut for this keyboard input
       Maybe<KeyboardShortcut> shortcut = mKeyboardMap.FindMatch(keyInput);
@@ -1736,18 +1736,19 @@ nsEventStatus APZCTreeManager::ProcessTo
     mApzcForInputBlock = GetTouchInputBlockAPZC(
         aInput, &touchBehaviors, &mHitResultForInputBlock, &aInput.mLayersId,
         &hitScrollbarNode);
 
     // Check if this event starts a scrollbar touch-drag. The conditions
     // checked are similar to the ones we check for MOUSE_INPUT starting
     // a scrollbar mouse-drag.
     mInScrollbarTouchDrag =
-        StaticPrefs::APZDragEnabled() && StaticPrefs::APZTouchDragEnabled() &&
-        hitScrollbarNode && hitScrollbarNode->IsScrollThumbNode() &&
+        StaticPrefs::apz_drag_enabled() &&
+        StaticPrefs::apz_touch_drag_enabled() && hitScrollbarNode &&
+        hitScrollbarNode->IsScrollThumbNode() &&
         hitScrollbarNode->GetScrollbarData().mThumbIsAsyncDraggable;
 
     MOZ_ASSERT(touchBehaviors.Length() == aInput.mTouches.Length());
     for (size_t i = 0; i < touchBehaviors.Length(); i++) {
       APZCTM_LOG("Touch point has allowed behaviours 0x%02x\n",
                  touchBehaviors[i]);
       if (touchBehaviors[i] == AllowedTouchBehavior::UNKNOWN) {
         // If there's any unknown items in the list, throw it out and we'll
@@ -1919,17 +1920,17 @@ void APZCTreeManager::SetupScrollbarDrag
 
   // Record the thumb's position at the start of the drag.
   // We snap back to this position if, during the drag, the mouse
   // gets sufficiently far away from the scrollbar.
   dragBlock->SetInitialThumbPos(thumbData.mThumbStart);
 
   // Under some conditions, we can confirm the drag block right away.
   // Otherwise, we have to wait for a main-thread confirmation.
-  if (StaticPrefs::APZDragInitiationEnabled() &&
+  if (StaticPrefs::apz_drag_initial_enabled() &&
       // check that the scrollbar's target scroll frame is layerized
       aScrollThumbNode->GetScrollTargetId() == aApzc->GetGuid().mScrollId &&
       !aApzc->IsScrollInfoLayer()) {
     uint64_t dragBlockId = dragBlock->GetBlockId();
     // AsyncPanZoomController::HandleInputEvent() will call
     // TransformToLocal() on the event, but we need its mLocalOrigin now
     // to compute a drag start offset for the AsyncDragMetrics.
     aMouseInput.TransformToLocal(aApzc->GetTransformToThis());
@@ -2383,17 +2384,17 @@ void APZCTreeManager::DispatchScroll(
     }
   }
 }
 
 ParentLayerPoint APZCTreeManager::DispatchFling(
     AsyncPanZoomController* aPrev, const FlingHandoffState& aHandoffState) {
   // If immediate handoff is disallowed, do not allow handoff beyond the
   // single APZC that's scrolled by the input block that triggered this fling.
-  if (aHandoffState.mIsHandoff && !StaticPrefs::APZAllowImmediateHandoff() &&
+  if (aHandoffState.mIsHandoff && !StaticPrefs::apz_allow_immediate_handoff() &&
       aHandoffState.mScrolledApzc == aPrev) {
     FLING_LOG("APZCTM dropping handoff due to disallowed immediate handoff\n");
     return aHandoffState.mVelocity;
   }
 
   const OverscrollHandoffChain* chain = aHandoffState.mChain;
   RefPtr<AsyncPanZoomController> current;
   uint32_t overscrollHandoffChainLength = chain->Length();

--- a/gfx/layers/apz/src/APZInputBridge.cpp
+++ b/gfx/layers/apz/src/APZInputBridge.cpp
@@ -60,17 +60,17 @@ nsEventStatus APZInputBridge::ReceiveInp
 
       // If zooming is enabled, mark the mouse event as "ignore root
       // scroll frame". This ensures that the main-thread hit test the
       // mouse event undergoes (in PositionedEventTargeting.cpp) uses
       // the IGNORE_ROOT_SCROLL_FRAME flag, which is needed for correct
       // hit testing in a zoomed-in or zoomed-out state.
       // FIXME: bug 1525793 -- this may need to handle zooming or not on a
       // per-document basis.
-      if (StaticPrefs::APZAllowZooming()) {
+      if (StaticPrefs::apz_allow_zooming()) {
         mouseEvent.mIgnoreRootScrollFrame = true;
       }
 
       if (WillHandleMouseEvent(mouseEvent)) {
         MouseInput input(mouseEvent);
         input.mOrigin =
             ScreenPoint(mouseEvent.mRefPoint.x, mouseEvent.mRefPoint.y);
 

--- a/gfx/layers/apz/src/AndroidAPZ.cpp
+++ b/gfx/layers/apz/src/AndroidAPZ.cpp
@@ -50,39 +50,40 @@ AndroidSpecificState::AndroidSpecificSta
     return;
   }
   mOverScroller = scroller;
 }
 
 AsyncPanZoomAnimation* AndroidSpecificState::CreateFlingAnimation(
     AsyncPanZoomController& aApzc, const FlingHandoffState& aHandoffState,
     float aPLPPI) {
-  if (StaticPrefs::APZUseChromeFlingPhysics()) {
+  if (StaticPrefs::apz_android_chrome_fling_physics_enabled()) {
     return new GenericFlingAnimation<AndroidFlingPhysics>(
         aApzc, aHandoffState.mChain, aHandoffState.mIsHandoff,
         aHandoffState.mScrolledApzc, aPLPPI);
   } else {
     return new StackScrollerFlingAnimation(aApzc, this, aHandoffState.mChain,
                                            aHandoffState.mIsHandoff,
                                            aHandoffState.mScrolledApzc);
   }
 }
 
 UniquePtr<VelocityTracker> AndroidSpecificState::CreateVelocityTracker(
     Axis* aAxis) {
-  if (StaticPrefs::APZUseChromeFlingPhysics()) {
+  if (StaticPrefs::apz_android_chrome_fling_physics_enabled()) {
     return MakeUnique<AndroidVelocityTracker>();
   }
   return MakeUnique<SimpleVelocityTracker>(aAxis);
 }
 
 /* static */
 void AndroidSpecificState::InitializeGlobalState() {
-  // Not conditioned on StaticPrefs::APZUseChromeFlingPhysics() because
-  // the pref is live.
+  // Not conditioned on
+  // StaticPrefs::apz_android_chrome_fling_physics_enabled() because the pref
+  // is live.
   AndroidFlingPhysics::InitializeGlobalState();
 }
 
 const float BOUNDS_EPSILON = 1.0f;
 
 // This function is used to convert the scroll offset from a float to an integer
 // suitable for using with the Android OverScroller Class.
 // The Android OverScroller class (unfortunately) operates in integers instead
@@ -162,18 +163,19 @@ StackScrollerFlingAnimation::StackScroll
   int32_t originY =
       ClampStart(mStartOffset.y, scrollRangeStartY, scrollRangeEndY);
   if (!state->mLastFling.IsNull()) {
     // If it's been too long since the previous fling, or if the new fling's
     // velocity is too low, don't allow flywheel to kick in. If we do allow
     // flywheel to kick in, then we need to update the timestamp on the
     // StackScroller because otherwise it might use a stale velocity.
     TimeDuration flingDuration = TimeStamp::Now() - state->mLastFling;
-    if (flingDuration.ToMilliseconds() < StaticPrefs::APZFlingAccelInterval() &&
-        velocity.Length() >= StaticPrefs::APZFlingAccelMinVelocity()) {
+    if (flingDuration.ToMilliseconds() <
+            StaticPrefs::apz_fling_accel_interval_ms() &&
+        velocity.Length() >= StaticPrefs::apz_fling_accel_interval_ms()) {
       bool unused = false;
       mOverScroller->ComputeScrollOffset(flingDuration.ToMilliseconds(),
                                          &unused);
     } else {
       mOverScroller->ForceFinished(true);
     }
   }
   mOverScroller->Fling(
@@ -237,19 +239,19 @@ bool StackScrollerFlingAnimation::DoSamp
     shouldContinueFling = false;
   } else if (hitBoundX && hitBoundY) {
     // We can't scroll any farther along either axis.
     shouldContinueFling = false;
   }
 
   float speed = velocity.Length();
 
-  // StaticPrefs::APZFlingStoppedThreshold is only used in tests.
+  // StaticPrefs::apz_fling_stopped_threshold is only used in tests.
   if (!shouldContinueFling ||
-      (speed < StaticPrefs::APZFlingStoppedThreshold())) {
+      (speed < StaticPrefs::apz_fling_stopped_threshold())) {
     if (shouldContinueFling) {
       // The OverScroller thinks it should continue but the speed is below
       // the stopping threshold so abort the animation.
       mOverScroller->AbortAnimation();
     }
     // This animation is going to end. If DeferHandleFlingOverscroll
     // has not been called and there is still some velocity left,
     // call it so that fling hand off may occur if applicable.

--- a/gfx/layers/apz/src/AndroidFlingPhysics.cpp
+++ b/gfx/layers/apz/src/AndroidFlingPhysics.cpp
@@ -28,38 +28,39 @@ static double ComputeDeceleration(float 
          * kFriction;
 }
 
 // == std::log(0.78f) / std::log(0.9f)
 const float kDecelerationRate = 2.3582018f;
 
 // Default friction constant in android.view.ViewConfiguration.
 static float GetFlingFriction() {
-  return StaticPrefs::APZChromeFlingPhysicsFriction();
+  return StaticPrefs::apz_android_chrome_fling_physics_friction();
 }
 
 // Tension lines cross at (GetInflexion(), 1).
 static float GetInflexion() {
   // Clamp the inflexion to the range [0,1]. Values outside of this range
   // do not make sense in the physics model, and for negative values the
   // approximation used to compute the spline curve does not converge.
-  const float inflexion = StaticPrefs::APZChromeFlingPhysicsInflexion();
+  const float inflexion =
+      StaticPrefs::apz_android_chrome_fling_physics_inflexion();
   if (inflexion < 0.0f) {
     return 0.0f;
   }
   if (inflexion > 1.0f) {
     return 1.0f;
   }
   return inflexion;
 }
 
 // Fling scroll is stopped when the scroll position is |kThresholdForFlingEnd|
 // pixels or closer from the end.
 static float GetThresholdForFlingEnd() {
-  return StaticPrefs::APZChromeFlingPhysicsStopThreshold();
+  return StaticPrefs::apz_android_chrome_fling_physics_stop_threshold();
 }
 
 static double ComputeSplineDeceleration(ParentLayerCoord aVelocity,
                                         double aTuningCoeff) {
   float velocityPerSec = aVelocity * 1000.0f;
   return std::log(GetInflexion() * velocityPerSec /
                   (GetFlingFriction() * aTuningCoeff));
 }

--- a/gfx/layers/apz/src/AndroidVelocityTracker.cpp
+++ b/gfx/layers/apz/src/AndroidVelocityTracker.cpp
@@ -246,17 +246,17 @@ Maybe<float> AndroidVelocityTracker::Com
   }
 
   // Iterate over movement samples in reverse time order and collect samples.
   float pos[kHistorySize];
   float w[kHistorySize];
   float time[kHistorySize];
   uint32_t m = 0;
   int index = mHistory.Length() - 1;
-  const uint32_t horizon = StaticPrefs::APZVelocityRelevanceTime();
+  const uint32_t horizon = StaticPrefs::apz_velocity_relevance_time_ms();
   const auto& newest_movement = mHistory[index];
 
   do {
     const auto& movement = mHistory[index];
     uint32_t age = newest_movement.first - movement.first;
     if (age > horizon) break;
 
     ParentLayerCoord position = movement.second;

--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -610,17 +610,17 @@ AutoApplyAsyncTestAttributes::~AutoApply
 class ZoomAnimation : public AsyncPanZoomAnimation {
  public:
   ZoomAnimation(AsyncPanZoomController& aApzc, const CSSPoint& aStartOffset,
                 const CSSToParentLayerScale2D& aStartZoom,
                 const CSSPoint& aEndOffset,
                 const CSSToParentLayerScale2D& aEndZoom)
       : mApzc(aApzc),
         mTotalDuration(TimeDuration::FromMilliseconds(
-            StaticPrefs::APZZoomAnimationDuration())),
+            StaticPrefs::apz_zoom_animation_duration_ms())),
         mStartOffset(aStartOffset),
         mStartZoom(aStartZoom),
         mEndOffset(aEndOffset),
         mEndZoom(aEndZoom) {}
 
   virtual bool DoSample(FrameMetrics& aFrameMetrics,
                         const TimeDuration& aDelta) override {
     mDuration += aDelta;
@@ -810,19 +810,21 @@ void AsyncPanZoomController::InitializeG
   if (sInitialized) return;
   sInitialized = true;
 
   MOZ_ASSERT(NS_IsMainThread());
 
   gZoomAnimationFunction =
       new ComputedTimingFunction(nsTimingFunction(StyleTimingKeyword::Ease));
   ClearOnShutdown(&gZoomAnimationFunction);
-  gVelocityCurveFunction = new ComputedTimingFunction(nsTimingFunction(
-      StaticPrefs::APZCurveFunctionX1(), StaticPrefs::APZCurveFunctionY1(),
-      StaticPrefs::APZCurveFunctionX2(), StaticPrefs::APZCurveFunctionY2()));
+  gVelocityCurveFunction = new ComputedTimingFunction(
+      nsTimingFunction(StaticPrefs::apz_fling_curve_function_x1(),
+                       StaticPrefs::apz_fling_curve_function_y1(),
+                       StaticPrefs::apz_fling_curve_function_x2(),
+                       StaticPrefs::apz_fling_curve_function_y2()));
   ClearOnShutdown(&gVelocityCurveFunction);
 
   uint64_t sysmem = PR_GetPhysicalMemorySize();
   uint64_t threshold = 1LL << 32;  // 4 GB in bytes
   gIsHighMemSystem = sysmem >= threshold;
 
   PlatformSpecificState::InitializeGlobalState();
 }
@@ -840,17 +842,17 @@ AsyncPanZoomController::AsyncPanZoomCont
       mTreeManager(aTreeManager),
       mRecursiveMutex("AsyncPanZoomController"),
       mLastContentPaintMetrics(mLastContentPaintMetadata.GetMetrics()),
       mX(this),
       mY(this),
       mPanDirRestricted(false),
       mPinchLocked(false),
       mPinchEventBuffer(TimeDuration::FromMilliseconds(
-          StaticPrefs::APZPinchLockBufferMaxAge())),
+          StaticPrefs::apz_pinch_lock_buffer_max_age())),
       mZoomConstraints(false, false,
                        mScrollMetadata.GetMetrics().GetDevPixelsPerCSSPixel() *
                            kViewportMinScale / ParentLayerToScreenScale(1),
                        mScrollMetadata.GetMetrics().GetDevPixelsPerCSSPixel() *
                            kViewportMaxScale / ParentLayerToScreenScale(1)),
       mLastSampleTime(GetFrameTime()),
       mLastCheckerboardReport(GetFrameTime()),
       mOverscrollEffect(MakeUnique<OverscrollEffect>(*this)),
@@ -933,35 +935,35 @@ float AsyncPanZoomController::GetDPI() c
   }
   // If this APZC has been destroyed then this value is not going to be
   // used for anything that the user will end up seeing, so we can just
   // return 0.
   return 0.0;
 }
 
 ScreenCoord AsyncPanZoomController::GetTouchStartTolerance() const {
-  return (StaticPrefs::APZTouchStartTolerance() * GetDPI());
+  return (StaticPrefs::apz_touch_start_tolerance() * GetDPI());
 }
 
 ScreenCoord AsyncPanZoomController::GetTouchMoveTolerance() const {
-  return (StaticPrefs::APZTouchMoveTolerance() * GetDPI());
+  return (StaticPrefs::apz_touch_move_tolerance() * GetDPI());
 }
 
 ScreenCoord AsyncPanZoomController::GetSecondTapTolerance() const {
-  return (StaticPrefs::APZSecondTapTolerance() * GetDPI());
+  return (StaticPrefs::apz_second_tap_tolerance() * GetDPI());
 }
 
 /* static */ AsyncPanZoomController::AxisLockMode
 AsyncPanZoomController::GetAxisLockMode() {
-  return static_cast<AxisLockMode>(StaticPrefs::APZAxisLockMode());
+  return static_cast<AxisLockMode>(StaticPrefs::apz_axis_lock_mode());
 }
 
 /* static */ AsyncPanZoomController::PinchLockMode
 AsyncPanZoomController::GetPinchLockMode() {
-  return static_cast<PinchLockMode>(StaticPrefs::APZPinchLockMode());
+  return static_cast<PinchLockMode>(StaticPrefs::apz_pinch_lock_mode());
 }
 
 bool AsyncPanZoomController::ArePointerEventsConsumable(
     TouchBlockState* aBlock, const MultiTouchInput& aInput) {
   uint32_t touchPoints = aInput.mTouches.Length();
   if (touchPoints == 0) {
     // Cant' do anything with zero touch points
     return false;
@@ -1007,17 +1009,17 @@ bool AsyncPanZoomController::ArePointerE
   zoomable &= (aBlock->TouchActionAllowsPinchZoom());
 
   return pannable || zoomable;
 }
 
 nsEventStatus AsyncPanZoomController::HandleDragEvent(
     const MouseInput& aEvent, const AsyncDragMetrics& aDragMetrics,
     CSSCoord aInitialThumbPos) {
-  if (!StaticPrefs::APZDragEnabled()) {
+  if (!StaticPrefs::apz_drag_enabled()) {
     return nsEventStatus_eIgnore;
   }
 
   if (!GetApzcTreeManager()) {
     return nsEventStatus_eConsumeNoDefault;
   }
 
   if (aEvent.mType == MouseInput::MouseType::MOUSE_UP) {
@@ -1561,17 +1563,17 @@ nsEventStatus AsyncPanZoomController::On
     mX.StartTouch(aEvent.mLocalFocusPoint.x, aEvent.mTime);
     mY.StartTouch(aEvent.mLocalFocusPoint.y, aEvent.mTime);
   }
 
   // For platforms that don't support APZ zooming, dispatch a message to the
   // content controller, it may want to do something else with this gesture.
   // FIXME: bug 1525793 -- this may need to handle zooming or not on a
   // per-document basis.
-  if (!StaticPrefs::APZAllowZooming()) {
+  if (!StaticPrefs::apz_allow_zooming()) {
     if (RefPtr<GeckoContentController> controller =
             GetGeckoContentController()) {
       controller->NotifyPinchGesture(aEvent.mType, GetGuid(), 0,
                                      aEvent.modifiers);
     }
   }
 
   SetState(PINCHING);
@@ -1608,17 +1610,17 @@ nsEventStatus AsyncPanZoomController::On
   // it cannot be called while the mRecursiveMutex lock is held.
   if (!allowZoom) {
     mX.UpdateWithTouchAtDevicePoint(aEvent.mLocalFocusPoint.x, aEvent.mTime);
     mY.UpdateWithTouchAtDevicePoint(aEvent.mLocalFocusPoint.y, aEvent.mTime);
   }
 
   // FIXME: bug 1525793 -- this may need to handle zooming or not on a
   // per-document basis.
-  if (!StaticPrefs::APZAllowZooming()) {
+  if (!StaticPrefs::apz_allow_zooming()) {
     if (RefPtr<GeckoContentController> controller =
             GetGeckoContentController()) {
       controller->NotifyPinchGesture(
           aEvent.mType, GetGuid(),
           ViewAs<LayoutDevicePixel>(
               aEvent.mCurrentSpan - aEvent.mPreviousSpan,
               PixelCastJustification::LayoutDeviceIsParentLayerForRCDRSF),
           aEvent.modifiers);
@@ -1698,17 +1700,17 @@ nsEventStatus AsyncPanZoomController::On
       ScaleWithFocus(spanRatio, cssFocusPoint);
 
       if (neededDisplacement != CSSPoint()) {
         ScrollBy(neededDisplacement);
       }
 
       // We don't want to redraw on every scale, so throttle it.
       if (!mPinchPaintTimerSet) {
-        const int delay = StaticPrefs::APZScaleRepaintDelay();
+        const int delay = StaticPrefs::apz_scale_repaint_delay_ms();
         if (delay >= 0) {
           if (RefPtr<GeckoContentController> controller =
                   GetGeckoContentController()) {
             mPinchPaintTimerSet = true;
             controller->PostDelayedTask(
                 NewRunnableMethod(
                     "layers::AsyncPanZoomController::"
                     "DoDelayedRequestContentRepaint",
@@ -1742,17 +1744,17 @@ nsEventStatus AsyncPanZoomController::On
 
   if (HasReadyTouchBlock() &&
       !GetCurrentTouchBlock()->TouchActionAllowsPinchZoom()) {
     return nsEventStatus_eIgnore;
   }
 
   // FIXME: bug 1525793 -- this may need to handle zooming or not on a
   // per-document basis.
-  if (!StaticPrefs::APZAllowZooming()) {
+  if (!StaticPrefs::apz_allow_zooming()) {
     if (RefPtr<GeckoContentController> controller =
             GetGeckoContentController()) {
       controller->NotifyPinchGesture(aEvent.mType, GetGuid(), 0,
                                      aEvent.modifiers);
     }
   }
 
   {
@@ -1835,19 +1837,20 @@ nsEventStatus AsyncPanZoomController::Ha
   // if DispatchFling() gives the fling to somone else. However,
   // don't send the state change notification until we've determined
   // what our final state is to avoid notification churn.
   StateChangeNotificationBlocker blocker(this);
   SetState(NOTHING);
 
   APZC_LOG("%p starting a fling animation if %f >= %f\n", this,
            flingVelocity.Length().value,
-           StaticPrefs::APZFlingMinVelocityThreshold());
-
-  if (flingVelocity.Length() < StaticPrefs::APZFlingMinVelocityThreshold()) {
+           StaticPrefs::apz_fling_min_velocity_threshold());
+
+  if (flingVelocity.Length() <
+      StaticPrefs::apz_fling_min_velocity_threshold()) {
     // Relieve overscroll now if needed, since we will not transition to a fling
     // animation and then an overscroll animation, and relieve it then.
     GetCurrentInputBlock()
         ->GetOverscrollHandoffChain()
         ->SnapBackOverscrolledApzc(this);
     return nsEventStatus_eConsumeNoDefault;
   }
 
@@ -2249,17 +2252,17 @@ bool AsyncPanZoomController::IsContentOf
     return mScrollMetadata.IsAutoDirRootContentRTL();
   }
   RecursiveMutexAutoLock lock(mRecursiveMutex);
   return Metrics().IsHorizontalContentRightToLeft();
 }
 
 bool AsyncPanZoomController::AllowScrollHandoffInCurrentBlock() const {
   bool result = mInputQueue->AllowScrollHandoff();
-  if (!StaticPrefs::APZAllowImmediateHandoff()) {
+  if (!StaticPrefs::apz_allow_immediate_handoff()) {
     if (InputBlockState* currentBlock = GetCurrentInputBlock()) {
       // Do not allow handoff beyond the first APZC to scroll.
       if (currentBlock->GetScrolledApzc() == this) {
         result = false;
         APZC_LOG("%p dropping handoff; AllowImmediateHandoff=false\n", this);
       }
     }
   }
@@ -2925,47 +2928,48 @@ void AsyncPanZoomController::HandlePanni
   bool canScrollHorizontal =
       !mX.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection(
                                 this, ScrollDirection::eHorizontal);
   bool canScrollVertical =
       !mY.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection(
                                 this, ScrollDirection::eVertical);
   if (GetCurrentTouchBlock()->TouchActionAllowsPanningXY()) {
     if (canScrollHorizontal && canScrollVertical) {
-      if (apz::IsCloseToHorizontal(aAngle, StaticPrefs::APZAxisLockAngle())) {
+      if (apz::IsCloseToHorizontal(aAngle,
+                                   StaticPrefs::apz_axis_lock_lock_angle())) {
         mY.SetAxisLocked(true);
         SetState(PANNING_LOCKED_X);
-      } else if (apz::IsCloseToVertical(aAngle,
-                                        StaticPrefs::APZAxisLockAngle())) {
+      } else if (apz::IsCloseToVertical(
+                     aAngle, StaticPrefs::apz_axis_lock_lock_angle())) {
         mX.SetAxisLocked(true);
         SetState(PANNING_LOCKED_Y);
       } else {
         SetState(PANNING);
       }
     } else if (canScrollHorizontal || canScrollVertical) {
       SetState(PANNING);
     } else {
       SetState(NOTHING);
     }
   } else if (GetCurrentTouchBlock()->TouchActionAllowsPanningX()) {
     // Using bigger angle for panning to keep behavior consistent
     // with IE.
-    if (apz::IsCloseToHorizontal(aAngle,
-                                 StaticPrefs::APZAllowedDirectPanAngle())) {
+    if (apz::IsCloseToHorizontal(
+            aAngle, StaticPrefs::apz_axis_lock_direct_pan_angle())) {
       mY.SetAxisLocked(true);
       SetState(PANNING_LOCKED_X);
       mPanDirRestricted = true;
     } else {
       // Don't treat these touches as pan/zoom movements since 'touch-action'
       // value requires it.
       SetState(NOTHING);
     }
   } else if (GetCurrentTouchBlock()->TouchActionAllowsPanningY()) {
     if (apz::IsCloseToVertical(aAngle,
-                               StaticPrefs::APZAllowedDirectPanAngle())) {
+                               StaticPrefs::apz_axis_lock_direct_pan_angle())) {
       mX.SetAxisLocked(true);
       SetState(PANNING_LOCKED_Y);
       mPanDirRestricted = true;
     } else {
       SetState(NOTHING);
     }
   } else {
     SetState(NOTHING);
@@ -2988,23 +2992,24 @@ void AsyncPanZoomController::HandlePanni
       !mX.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection(
                                 this, ScrollDirection::eHorizontal);
   bool canScrollVertical =
       !mY.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection(
                                 this, ScrollDirection::eVertical);
 
   if (!canScrollHorizontal || !canScrollVertical) {
     SetState(PANNING);
-  } else if (apz::IsCloseToHorizontal(aAngle,
-                                      StaticPrefs::APZAxisLockAngle())) {
+  } else if (apz::IsCloseToHorizontal(
+                 aAngle, StaticPrefs::apz_axis_lock_lock_angle())) {
     mY.SetAxisLocked(true);
     if (canScrollHorizontal) {
       SetState(PANNING_LOCKED_X);
     }
-  } else if (apz::IsCloseToVertical(aAngle, StaticPrefs::APZAxisLockAngle())) {
+  } else if (apz::IsCloseToVertical(aAngle,
+                                    StaticPrefs::apz_axis_lock_lock_angle())) {
     mX.SetAxisLocked(true);
     if (canScrollVertical) {
       SetState(PANNING_LOCKED_Y);
     }
   } else {
     SetState(PANNING);
   }
 }
@@ -3014,29 +3019,30 @@ void AsyncPanZoomController::HandlePanni
   // If we're axis-locked, check if the user is trying to break the lock
   if (GetAxisLockMode() == STICKY && !mPanDirRestricted) {
     ParentLayerPoint vector =
         ToParentLayerCoordinates(aPanDistance, mStartTouch);
 
     double angle = atan2(vector.y, vector.x);  // range [-pi, pi]
     angle = fabs(angle);                       // range [0, pi]
 
-    float breakThreshold = StaticPrefs::APZAxisBreakoutThreshold() * GetDPI();
+    float breakThreshold =
+        StaticPrefs::apz_axis_lock_breakout_threshold() * GetDPI();
 
     if (fabs(aPanDistance.x) > breakThreshold ||
         fabs(aPanDistance.y) > breakThreshold) {
       if (mState == PANNING_LOCKED_X) {
-        if (!apz::IsCloseToHorizontal(angle,
-                                      StaticPrefs::APZAxisBreakoutAngle())) {
+        if (!apz::IsCloseToHorizontal(
+                angle, StaticPrefs::apz_axis_lock_breakout_angle())) {
           mY.SetAxisLocked(false);
           SetState(PANNING);
         }
       } else if (mState == PANNING_LOCKED_Y) {
-        if (!apz::IsCloseToVertical(angle,
-                                    StaticPrefs::APZAxisBreakoutAngle())) {
+        if (!apz::IsCloseToVertical(
+                angle, StaticPrefs::apz_axis_lock_breakout_angle())) {
           mX.SetAxisLocked(false);
           SetState(PANNING);
         }
       }
     }
   }
 }
 
@@ -3070,25 +3076,25 @@ void AsyncPanZoomController::HandlePinch
       ToScreenCoordinates(ParentLayerPoint(0, bufferedSpanDistance), focusPoint)
           .Length();
   ScreenPoint focusChange =
       ToScreenCoordinates(bufferedFocusChange, focusPoint);
 
   if (mPinchLocked) {
     if (GetPinchLockMode() == PINCH_STICKY) {
       ScreenCoord spanBreakoutThreshold =
-          StaticPrefs::APZPinchLockSpanBreakoutThreshold() * GetDPI();
+          StaticPrefs::apz_pinch_lock_span_breakout_threshold() * GetDPI();
       mPinchLocked = !(spanDistance > spanBreakoutThreshold);
     }
   } else {
     if (GetPinchLockMode() != PINCH_FREE) {
       ScreenCoord spanLockThreshold =
-          StaticPrefs::APZPinchLockSpanLockThreshold() * GetDPI();
+          StaticPrefs::apz_pinch_lock_span_lock_threshold() * GetDPI();
       ScreenCoord scrollLockThreshold =
-          StaticPrefs::APZPinchLockScrollLockThreshold() * GetDPI();
+          StaticPrefs::apz_pinch_lock_scroll_lock_threshold() * GetDPI();
 
       if (spanDistance < spanLockThreshold &&
           focusChange.Length() > scrollLockThreshold) {
         mPinchLocked = true;
       }
     }
   }
 }
@@ -3252,30 +3258,30 @@ bool AsyncPanZoomController::AttemptScro
 
 void AsyncPanZoomController::OverscrollForPanning(
     ParentLayerPoint& aOverscroll, const ScreenPoint& aPanDistance) {
   // Only allow entering overscroll along an axis if the pan distance along
   // that axis is greater than the pan distance along the other axis by a
   // configurable factor. If we are already overscrolled, don't check this.
   if (!IsOverscrolled()) {
     if (aPanDistance.x <
-        StaticPrefs::APZMinPanDistanceRatio() * aPanDistance.y) {
+        StaticPrefs::apz_overscroll_min_pan_distance_ratio() * aPanDistance.y) {
       aOverscroll.x = 0;
     }
     if (aPanDistance.y <
-        StaticPrefs::APZMinPanDistanceRatio() * aPanDistance.x) {
+        StaticPrefs::apz_overscroll_min_pan_distance_ratio() * aPanDistance.x) {
       aOverscroll.y = 0;
     }
   }
 
   OverscrollBy(aOverscroll);
 }
 
 void AsyncPanZoomController::OverscrollBy(ParentLayerPoint& aOverscroll) {
-  if (!StaticPrefs::APZOverscrollEnabled()) {
+  if (!StaticPrefs::apz_overscroll_enabled()) {
     return;
   }
 
   RecursiveMutexAutoLock lock(mRecursiveMutex);
   // Do not go into overscroll in a direction in which we have no room to
   // scroll to begin with.
   bool xCanScroll = mX.CanScroll();
   bool yCanScroll = mY.CanScroll();
@@ -3332,17 +3338,17 @@ ParentLayerPoint AsyncPanZoomController:
   }
 
   // If we're not scrollable in at least one of the directions in which we
   // were handed velocity, don't start a fling animation.
   // The |IsFinite()| condition should only fail when running some tests
   // that generate events faster than the clock resolution.
   ParentLayerPoint velocity = GetVelocityVector();
   if (!velocity.IsFinite() ||
-      velocity.Length() < StaticPrefs::APZFlingMinVelocityThreshold()) {
+      velocity.Length() < StaticPrefs::apz_fling_min_velocity_threshold()) {
     // Relieve overscroll now if needed, since we will not transition to a fling
     // animation and then an overscroll animation, and relieve it then.
     aHandoffState.mChain->SnapBackOverscrolledApzc(this);
     return residualVelocity;
   }
 
   // If there's a scroll snap point near the predicted fling destination,
   // scroll there using a smooth scroll animation. Otherwise, start a
@@ -3403,17 +3409,17 @@ void AsyncPanZoomController::HandleFling
   if (treeManagerLocal) {
     const FlingHandoffState handoffState{aVelocity, aOverscrollHandoffChain,
                                          true /* handoff */, aScrolledApzc};
     ParentLayerPoint residualVelocity =
         treeManagerLocal->DispatchFling(this, handoffState);
     FLING_LOG("APZC %p left with residual velocity %s\n", this,
               Stringify(residualVelocity).c_str());
     if (!IsZero(residualVelocity) && IsPannable() &&
-        StaticPrefs::APZOverscrollEnabled()) {
+        StaticPrefs::apz_overscroll_enabled()) {
       // Obey overscroll-behavior.
       RecursiveMutexAutoLock lock(mRecursiveMutex);
       if (!mX.OverscrollBehaviorAllowsOverscrollEffect()) {
         residualVelocity.x = 0;
       }
       if (!mY.OverscrollBehaviorAllowsOverscrollEffect()) {
         residualVelocity.y = 0;
       }
@@ -3661,50 +3667,50 @@ void AsyncPanZoomController::ScaleWithFo
 }
 
 /**
  * Enlarges the displayport along both axes based on the velocity.
  */
 static CSSSize CalculateDisplayPortSize(const CSSSize& aCompositionSize,
                                         const CSSPoint& aVelocity) {
   bool xIsStationarySpeed =
-      fabsf(aVelocity.x) < StaticPrefs::APZMinSkateSpeed();
+      fabsf(aVelocity.x) < StaticPrefs::apz_min_skate_speed();
   bool yIsStationarySpeed =
-      fabsf(aVelocity.y) < StaticPrefs::APZMinSkateSpeed();
+      fabsf(aVelocity.y) < StaticPrefs::apz_min_skate_speed();
   float xMultiplier = xIsStationarySpeed
-                          ? StaticPrefs::APZXStationarySizeMultiplier()
-                          : StaticPrefs::APZXSkateSizeMultiplier();
+                          ? StaticPrefs::apz_x_stationary_size_multiplier()
+                          : StaticPrefs::apz_x_skate_size_multiplier();
   float yMultiplier = yIsStationarySpeed
-                          ? StaticPrefs::APZYStationarySizeMultiplier()
-                          : StaticPrefs::APZYSkateSizeMultiplier();
+                          ? StaticPrefs::apz_y_stationary_size_multiplier()
+                          : StaticPrefs::apz_y_skate_size_multiplier();
 
   if (IsHighMemSystem() && !xIsStationarySpeed) {
-    xMultiplier += StaticPrefs::APZXSkateHighMemAdjust();
+    xMultiplier += StaticPrefs::apz_x_skate_highmem_adjust();
   }
 
   if (IsHighMemSystem() && !yIsStationarySpeed) {
-    yMultiplier += StaticPrefs::APZYSkateHighMemAdjust();
+    yMultiplier += StaticPrefs::apz_y_skate_highmem_adjust();
   }
 
   return aCompositionSize * CSSSize(xMultiplier, yMultiplier);
 }
 
 /**
  * Ensures that the displayport is at least as large as the visible area
  * inflated by the danger zone. If this is not the case then the
  * "AboutToCheckerboard" function in TiledContentClient.cpp will return true
  * even in the stable state.
  */
 static CSSSize ExpandDisplayPortToDangerZone(
     const CSSSize& aDisplayPortSize, const FrameMetrics& aFrameMetrics) {
   CSSSize dangerZone(0.0f, 0.0f);
   if (aFrameMetrics.LayersPixelsPerCSSPixel().xScale != 0 &&
       aFrameMetrics.LayersPixelsPerCSSPixel().yScale != 0) {
-    dangerZone = LayerSize(StaticPrefs::APZDangerZoneX(),
-                           StaticPrefs::APZDangerZoneY()) /
+    dangerZone = LayerSize(StaticPrefs::apz_danger_zone_x(),
+                           StaticPrefs::apz_danger_zone_y()) /
                  aFrameMetrics.LayersPixelsPerCSSPixel();
   }
   const CSSSize compositionSize =
       aFrameMetrics.CalculateBoundedCompositedSizeInCssPixels();
 
   const float xSize = std::max(aDisplayPortSize.width,
                                compositionSize.width + (2 * dangerZone.width));
 
@@ -3754,17 +3760,17 @@ const ScreenMargin AsyncPanZoomControlle
 
   // Calculate the displayport size based on how fast we're moving along each
   // axis.
   CSSSize displayPortSize = CalculateDisplayPortSize(compositionSize, velocity);
 
   displayPortSize =
       ExpandDisplayPortToDangerZone(displayPortSize, aFrameMetrics);
 
-  if (StaticPrefs::APZEnlargeDisplayPortWhenClipped()) {
+  if (StaticPrefs::apz_enlarge_displayport_when_clipped()) {
     RedistributeDisplayPortExcess(displayPortSize, scrollableRect);
   }
 
   // We calculate a "displayport" here which is relative to the scroll offset.
   // Note that the scroll offset we have here in the APZ code may not be the
   // same as the base rect that gets used on the layout side when the
   // displayport margins are actually applied, so it is important to only
   // consider the displayport as margins relative to a scroll offset rather than
@@ -3773,17 +3779,17 @@ const ScreenMargin AsyncPanZoomControlle
   // Center the displayport based on its expansion over the composition size.
   CSSRect displayPort((compositionSize.width - displayPortSize.width) / 2.0f,
                       (compositionSize.height - displayPortSize.height) / 2.0f,
                       displayPortSize.width, displayPortSize.height);
 
   // Offset the displayport, depending on how fast we're moving and the
   // estimated time it takes to paint, to try to minimise checkerboarding.
   float paintFactor = kDefaultEstimatedPaintDurationMs;
-  displayPort.MoveBy(velocity * paintFactor * StaticPrefs::APZVelocityBias());
+  displayPort.MoveBy(velocity * paintFactor * StaticPrefs::apz_velocity_bias());
 
   APZC_LOG_FM(
       aFrameMetrics,
       "Calculated displayport as %s from velocity %s paint time %f metrics",
       Stringify(displayPort).c_str(), ToString(aVelocity).c_str(), paintFactor);
 
   CSSMargin cssMargins;
   cssMargins.left = -displayPort.X();
@@ -3838,17 +3844,17 @@ bool AsyncPanZoomController::SnapBackIfO
     ScrollSnap();
   }
   return false;
 }
 
 bool AsyncPanZoomController::IsFlingingFast() const {
   RecursiveMutexAutoLock lock(mRecursiveMutex);
   if (mState == FLING && GetVelocityVector().Length() >
-                             StaticPrefs::APZFlingStopOnTapThreshold()) {
+                             StaticPrefs::apz_fling_stop_on_tap_threshold()) {
     APZC_LOG("%p is moving fast\n", this);
     return true;
   }
   return false;
 }
 
 bool AsyncPanZoomController::IsPannable() const {
   RecursiveMutexAutoLock lock(mRecursiveMutex);
@@ -4201,17 +4207,17 @@ AsyncPanZoomController::GetCurrentAsyncT
   // double applied.
   AutoApplyAsyncTestAttributes testAttributeApplier(this);
 
   // Use the layout viewport to adjust fixed position elements if and only if
   // it's larger than the visual viewport (assuming we're scrolling the RCD-RSF
   // with apz.allow_zooming enabled).
   // FIXME: bug 1525793 -- this may need to handle zooming or not on a
   // per-document basis.
-  return (StaticPrefs::APZAllowZooming() && Metrics().IsRootContent() &&
+  return (StaticPrefs::apz_allow_zooming() && Metrics().IsRootContent() &&
           Metrics().GetVisualViewport().Size() <=
               Metrics().GetLayoutViewport().Size())
              ? GetCurrentAsyncViewportTransform(aMode)
              : GetCurrentAsyncTransform(aMode);
 }
 
 AsyncTransformComponentMatrix
 AsyncPanZoomController::GetCurrentAsyncTransformWithOverscroll(
@@ -4229,33 +4235,33 @@ LayoutDeviceToParentLayerScale AsyncPanZ
   // Note that in general the zoom might have different x- and y-scales.
   // However, this function in particular is only used on the WebRender codepath
   // for which the scales should always be the same.
   return scale.ToScaleFactor() / Metrics().GetDevPixelsPerCSSPixel();
 }
 
 CSSRect AsyncPanZoomController::GetEffectiveLayoutViewport(
     AsyncTransformConsumer aMode) const {
-  if (StaticPrefs::APZFrameDelayEnabled() && aMode == eForCompositing) {
+  if (StaticPrefs::apz_frame_delay_enabled() && aMode == eForCompositing) {
     return mCompositedLayoutViewport;
   }
   return Metrics().GetLayoutViewport();
 }
 
 CSSPoint AsyncPanZoomController::GetEffectiveScrollOffset(
     AsyncTransformConsumer aMode) const {
-  if (StaticPrefs::APZFrameDelayEnabled() && aMode == eForCompositing) {
+  if (StaticPrefs::apz_frame_delay_enabled() && aMode == eForCompositing) {
     return mCompositedScrollOffset;
   }
   return Metrics().GetScrollOffset();
 }
 
 CSSToParentLayerScale2D AsyncPanZoomController::GetEffectiveZoom(
     AsyncTransformConsumer aMode) const {
-  if (StaticPrefs::APZFrameDelayEnabled() && aMode == eForCompositing) {
+  if (StaticPrefs::apz_frame_delay_enabled() && aMode == eForCompositing) {
     return mCompositedZoom;
   }
   return Metrics().GetZoom();
 }
 
 bool AsyncPanZoomController::SampleCompositedAsyncTransform() {
   RecursiveMutexAutoLock lock(mRecursiveMutex);
   if (!mCompositedLayoutViewport.IsEqualEdges(Metrics().GetLayoutViewport()) ||
@@ -4341,17 +4347,17 @@ void AsyncPanZoomController::ReportCheck
   if (mLastCheckerboardReport == aSampleTime) {
     // This function will get called multiple times for each APZC on a single
     // composite (once for each layer it is attached to). Only report the
     // checkerboard once per composite though.
     return;
   }
   mLastCheckerboardReport = aSampleTime;
 
-  bool recordTrace = StaticPrefs::APZRecordCheckerboarding();
+  bool recordTrace = StaticPrefs::apz_record_checkerboarding();
   bool forTelemetry = Telemetry::CanRecordExtended();
   uint32_t magnitude = GetCheckerboardMagnitude();
 
   MutexAutoLock lock(mCheckerboardEventLock);
   if (!mCheckerboardEvent && (recordTrace || forTelemetry)) {
     mCheckerboardEvent = MakeUnique<CheckerboardEvent>(recordTrace);
   }
   mPotentialCheckerboardTracker.InTransform(IsTransformingState(mState));
@@ -4370,17 +4376,17 @@ void AsyncPanZoomController::UpdateCheck
     mozilla::Telemetry::Accumulate(mozilla::Telemetry::CHECKERBOARD_PEAK,
                                    mCheckerboardEvent->GetPeak());
     mozilla::Telemetry::Accumulate(
         mozilla::Telemetry::CHECKERBOARD_DURATION,
         (uint32_t)mCheckerboardEvent->GetDuration().ToMilliseconds());
 
     mPotentialCheckerboardTracker.CheckerboardDone();
 
-    if (StaticPrefs::APZRecordCheckerboarding()) {
+    if (StaticPrefs::apz_record_checkerboarding()) {
       // if the pref is enabled, also send it to the storage class. it may be
       // chosen for public display on about:checkerboard, the hall of fame for
       // checkerboard events.
       uint32_t severity = mCheckerboardEvent->GetSeverity();
       std::string log = mCheckerboardEvent->GetLog();
       CheckerboardEventStorage::Report(severity, log);
     }
     mCheckerboardEvent = nullptr;
@@ -4680,17 +4686,18 @@ void AsyncPanZoomController::NotifyLayer
       // Send an acknowledgement with the new scroll generation so that any
       // repaint requests later in this function go through.
       // Because of the scroll generation update, any inflight paint requests
       // are going to be ignored by layout, and so mExpectedGeckoMetrics becomes
       // incorrect for the purposes of calculating the LD transform. To correct
       // this we need to update mExpectedGeckoMetrics to be the last thing we
       // know was painted by Gecko.
       Maybe<CSSPoint> relativeDelta;
-      if (StaticPrefs::APZRelativeUpdate() && aLayerMetrics.IsRelative()) {
+      if (StaticPrefs::apz_relative_update_enabled() &&
+          aLayerMetrics.IsRelative()) {
         APZC_LOG("%p relative updating scroll offset from %s by %s\n", this,
                  ToString(Metrics().GetScrollOffset()).c_str(),
                  ToString(aLayerMetrics.GetScrollOffset() -
                           aLayerMetrics.GetBaseScrollOffset())
                      .c_str());
 
         // It's possible that the main thread has ignored an APZ scroll offset
         // update for the pending relative scroll that we have just received.
@@ -4755,17 +4762,18 @@ void AsyncPanZoomController::NotifyLayer
     // the scroll update acknowledgement.
 
     APZC_LOG("%p smooth scrolling from %s to %s in state %d\n", this,
              Stringify(Metrics().GetScrollOffset()).c_str(),
              Stringify(aLayerMetrics.GetSmoothScrollOffset()).c_str(), mState);
 
     // See comment on the similar code in the |if (scrollOffsetUpdated)| block
     // above.
-    if (StaticPrefs::APZRelativeUpdate() && aLayerMetrics.IsRelative()) {
+    if (StaticPrefs::apz_relative_update_enabled() &&
+        aLayerMetrics.IsRelative()) {
       Metrics().ApplyRelativeSmoothScrollUpdateFrom(aLayerMetrics);
     } else {
       Metrics().ApplySmoothScrollUpdateFrom(aLayerMetrics);
     }
     needContentRepaint = true;
     mExpectedGeckoMetrics = aLayerMetrics;
 
     SmoothScrollTo(Metrics().GetSmoothScrollOffset());
@@ -5292,17 +5300,17 @@ void AsyncPanZoomController::ScrollSnapN
 void AsyncPanZoomController::ScrollSnap() {
   RecursiveMutexAutoLock lock(mRecursiveMutex);
   ScrollSnapNear(Metrics().GetScrollOffset());
 }
 
 void AsyncPanZoomController::ScrollSnapToDestination() {
   RecursiveMutexAutoLock lock(mRecursiveMutex);
 
-  float friction = StaticPrefs::APZFlingFriction();
+  float friction = StaticPrefs::apz_fling_friction();
   ParentLayerPoint velocity(mX.GetVelocity(), mY.GetVelocity());
   ParentLayerPoint predictedDelta;
   // "-velocity / log(1.0 - friction)" is the integral of the deceleration
   // curve modeled for flings in the "Axis" class.
   if (velocity.x != 0.0f) {
     predictedDelta.x = -velocity.x / log(1.0 - friction);
   }
   if (velocity.y != 0.0f) {

--- a/gfx/layers/apz/src/AsyncPanZoomController.h
+++ b/gfx/layers/apz/src/AsyncPanZoomController.h
@@ -1157,19 +1157,19 @@ class AsyncPanZoomController {
   /**
    * Samples the composited async transform, making the result of
    * |GetCurrentAsyncTransform(eForCompositing)| and similar functions reflect
    * the async scroll offset and zoom stored in |Metrics()|.
    *
    * Returns true if the newly sampled value is different from the previously
    * sampled value.
    *
-   * (This is only relevant when |StaticPrefs::APZFrameDelayEnabled() == true|.
-   * Otherwise, GetCurrentAsyncTransform() always reflects what's stored in
-   * |Metrics()| immediately, without any delay.)
+   * (This is only relevant when StaticPrefs::apz_frame_delay_enabled() is
+   * true. Otherwise, GetCurrentAsyncTransform() always reflects what's stored
+   * in |Metrics()| immediately, without any delay.)
    */
   bool SampleCompositedAsyncTransform();
 
   /**
    * Returns the incremental transformation corresponding to the async
    * panning/zooming of the layout viewport (unlike GetCurrentAsyncTransform,
    * which deals with async movement of the visual viewport). That is, when
    * this transform is multiplied with the layer's existing transform, it will

--- a/gfx/layers/apz/src/DesktopFlingPhysics.h
+++ b/gfx/layers/apz/src/DesktopFlingPhysics.h
@@ -20,18 +20,18 @@ namespace layers {
 class DesktopFlingPhysics {
  public:
   void Init(const ParentLayerPoint& aStartingVelocity,
             float aPLPPI /* unused */) {
     mVelocity = aStartingVelocity;
   }
   void Sample(const TimeDuration& aDelta, ParentLayerPoint* aOutVelocity,
               ParentLayerPoint* aOutOffset) {
-    float friction = StaticPrefs::APZFlingFriction();
-    float threshold = StaticPrefs::APZFlingStoppedThreshold();
+    float friction = StaticPrefs::apz_fling_friction();
+    float threshold = StaticPrefs::apz_fling_stopped_threshold();
 
     mVelocity = ParentLayerPoint(
         ApplyFrictionOrCancel(mVelocity.x, aDelta, friction, threshold),
         ApplyFrictionOrCancel(mVelocity.y, aDelta, friction, threshold));
 
     *aOutVelocity = mVelocity;
     *aOutOffset = mVelocity * aDelta.ToMilliseconds();
   }

--- a/gfx/layers/apz/src/FocusTarget.cpp
+++ b/gfx/layers/apz/src/FocusTarget.cpp
@@ -133,17 +133,17 @@ FocusTarget::FocusTarget(PresShell* aRoo
   // If there is no focused element then event dispatch goes to the body of
   // the page if it exists or the root element.
   if (!keyEventTarget) {
     keyEventTarget = document->GetUnfocusedKeyEventTarget();
   }
 
   // Check if there are key event listeners that could prevent default or change
   // the focus or selection of the page.
-  if (StaticPrefs::APZKeyboardPassiveListeners()) {
+  if (StaticPrefs::apz_keyboard_passive_listeners()) {
     mFocusHasKeyEventListeners =
         HasListenersForNonPassiveKeyEvents(keyEventTarget.get());
   } else {
     mFocusHasKeyEventListeners = HasListenersForKeyEvents(keyEventTarget.get());
   }
 
   // Check if the key event target is content editable or if the document
   // is in design mode.

--- a/gfx/layers/apz/src/GenericFlingAnimation.h
+++ b/gfx/layers/apz/src/GenericFlingAnimation.h
@@ -89,18 +89,18 @@ class GenericFlingAnimation : public Asy
     // y-fling to get accelerated. Note that the acceleration code is only
     // applied on the APZC that initiates the fling; the accelerated velocities
     // are then handed off using the normal DispatchFling codepath. Acceleration
     // is only applied in the APZC that originated the fling, not in APZCs
     // further down the handoff chain during handoff.
     bool applyAcceleration = !aFlingIsHandedOff;
     if (applyAcceleration && !mApzc.mLastFlingTime.IsNull() &&
         (now - mApzc.mLastFlingTime).ToMilliseconds() <
-            StaticPrefs::APZFlingAccelInterval() &&
-        velocity.Length() >= StaticPrefs::APZFlingAccelMinVelocity()) {
+            StaticPrefs::apz_fling_accel_interval_ms() &&
+        velocity.Length() >= StaticPrefs::apz_fling_accel_min_velocity()) {
       if (velocity.x != 0 &&
           SameDirection(velocity.x, mApzc.mLastFlingVelocity.x)) {
         velocity.x = Accelerate(velocity.x, mApzc.mLastFlingVelocity.x);
         FLING_LOG("%p Applying fling x-acceleration from %f to %f (delta %f)\n",
                   &mApzc, mApzc.mX.GetVelocity(), velocity.x,
                   mApzc.mLastFlingVelocity.x);
         mApzc.mX.SetVelocity(velocity.x);
       }
@@ -215,18 +215,18 @@ class GenericFlingAnimation : public Asy
 
  private:
   static bool SameDirection(float aVelocity1, float aVelocity2) {
     return (aVelocity1 == 0.0f) || (aVelocity2 == 0.0f) ||
            (IsNegative(aVelocity1) == IsNegative(aVelocity2));
   }
 
   static float Accelerate(float aBase, float aSupplemental) {
-    return (aBase * StaticPrefs::APZFlingAccelBaseMultiplier()) +
-           (aSupplemental * StaticPrefs::APZFlingAccelSupplementalMultiplier());
+    return (aBase * StaticPrefs::apz_fling_accel_base_mult()) +
+           (aSupplemental * StaticPrefs::apz_fling_accel_supplemental_mult());
   }
 
   AsyncPanZoomController& mApzc;
   RefPtr<const OverscrollHandoffChain> mOverscrollHandoffChain;
   RefPtr<const AsyncPanZoomController> mScrolledApzc;
 };
 
 }  // namespace layers

--- a/gfx/layers/apz/src/GestureEventListener.cpp
+++ b/gfx/layers/apz/src/GestureEventListener.cpp
@@ -286,23 +286,23 @@ nsEventStatus GestureEventListener::Hand
         mSingleTapSent = Nothing();
         SetState(GESTURE_NONE);
       }
       break;
     }
 
     // The user has performed a double tap, but not lifted her finger.
     case GESTURE_SECOND_SINGLE_TOUCH_DOWN: {
-      // If touch has moved noticeably (within StaticPrefs::APZMaxTapTime()),
+      // If touch has moved noticeably (within StaticPrefs::apz_max_tap_time()),
       // change state.
       if (MoveDistanceIsLarge()) {
         CancelLongTapTimeoutTask();
         CancelMaxTapTimeoutTask();
         mSingleTapSent = Nothing();
-        if (!StaticPrefs::APZOneTouchPinchEnabled()) {
+        if (!StaticPrefs::apz_one_touch_pinch_enabled()) {
           // If the one-touch-pinch feature is disabled, bail out of the double-
           // tap gesture instead.
           SetState(GESTURE_NONE);
           break;
         }
 
         SetState(GESTURE_ONE_TOUCH_PINCH);
 
@@ -624,13 +624,13 @@ void GestureEventListener::CreateMaxTapT
   MOZ_ASSERT(block);
   RefPtr<CancelableRunnable> task = NewCancelableRunnableMethod<bool>(
       "layers::GestureEventListener::HandleInputTimeoutMaxTap", this,
       &GestureEventListener::HandleInputTimeoutMaxTap,
       block->IsDuringFastFling());
 
   mMaxTapTimeoutTask = task;
   mAsyncPanZoomController->PostDelayedTask(task.forget(),
-                                           StaticPrefs::APZMaxTapTime());
+                                           StaticPrefs::apz_max_tap_time());
 }
 
 }  // namespace layers
 }  // namespace mozilla

--- a/gfx/layers/apz/src/InputBlockState.cpp
+++ b/gfx/layers/apz/src/InputBlockState.cpp
@@ -145,17 +145,17 @@ bool InputBlockState::IsDownchainOf(Asyn
       seenA = true;
     }
   }
   return false;
 }
 
 void InputBlockState::SetScrolledApzc(AsyncPanZoomController* aApzc) {
   // An input block should only have one scrolled APZC.
-  MOZ_ASSERT(!mScrolledApzc || (StaticPrefs::APZAllowImmediateHandoff()
+  MOZ_ASSERT(!mScrolledApzc || (StaticPrefs::apz_allow_immediate_handoff()
                                     ? IsDownchainOf(mScrolledApzc, aApzc)
                                     : mScrolledApzc == aApzc));
 
   mScrolledApzc = aApzc;
 }
 
 AsyncPanZoomController* InputBlockState::GetScrolledApzc() const {
   return mScrolledApzc;
@@ -778,18 +778,18 @@ Maybe<ScrollDirection> TouchBlockState::
       aInput.mTouches.Length() != 1) {
     return Nothing();
   }
   ScreenPoint vector = aInput.mTouches[0].mScreenPoint - mSlopOrigin;
   double angle = atan2(vector.y, vector.x);  // range [-pi, pi]
   angle = fabs(angle);                       // range [0, pi]
 
   double angleThreshold = TouchActionAllowsPanningXY()
-                              ? StaticPrefs::APZAxisLockAngle()
-                              : StaticPrefs::APZAllowedDirectPanAngle();
+                              ? StaticPrefs::apz_axis_lock_lock_angle()
+                              : StaticPrefs::apz_axis_lock_direct_pan_angle();
   if (apz::IsCloseToHorizontal(angle, angleThreshold)) {
     return Some(ScrollDirection::eHorizontal);
   }
   if (apz::IsCloseToVertical(angle, angleThreshold)) {
     return Some(ScrollDirection::eVertical);
   }
   return Nothing();
 }

--- a/gfx/layers/apz/src/InputBlockState.h
+++ b/gfx/layers/apz/src/InputBlockState.h
@@ -103,17 +103,17 @@ class InputBlockState : public RefCounte
   RefPtr<AsyncPanZoomController> mTargetApzc;
   TargetConfirmationState mTargetConfirmed;
   bool mRequiresTargetConfirmation;
   const uint64_t mBlockId;
 
   // The APZC that was actually scrolled by events in this input block.
   // This is used in configurations where a single input block is only
   // allowed to scroll a single APZC (configurations where
-  // StaticPrefs::APZAllowImmediateHandoff() is false). Set the first time an
+  // StaticPrefs::apz_allow_immediate_handoff() is false). Set the first time an
   // input event in this block scrolls an APZC.
   RefPtr<AsyncPanZoomController> mScrolledApzc;
 
  protected:
   RefPtr<const OverscrollHandoffChain> mOverscrollHandoffChain;
 
   // Used to transform events from global screen space to |mTargetApzc|'s
   // screen space. It's cached at the beginning of the input block so that

--- a/gfx/layers/apz/src/InputQueue.cpp
+++ b/gfx/layers/apz/src/InputQueue.cpp
@@ -314,17 +314,17 @@ nsEventStatus InputQueue::ReceiveKeyboar
   }
 
   mQueuedInputs.AppendElement(MakeUnique<QueuedInput>(aEvent, *block));
 
   ProcessQueue();
 
   // If APZ is allowing passive listeners then we must dispatch the event to
   // content, otherwise we can consume the event.
-  return StaticPrefs::APZKeyboardPassiveListeners()
+  return StaticPrefs::apz_keyboard_passive_listeners()
              ? nsEventStatus_eConsumeDoDefault
              : nsEventStatus_eConsumeNoDefault;
 }
 
 static bool CanScrollTargetHorizontally(const PanGestureInput& aInitialEvent,
                                         PanGestureBlockState* aBlock) {
   PanGestureInput horizontalComponent = aInitialEvent;
   horizontalComponent.mPanDisplacement.y = 0;
@@ -547,17 +547,17 @@ bool InputQueue::IsDragOnScrollbar(bool 
 void InputQueue::ScheduleMainThreadTimeout(
     const RefPtr<AsyncPanZoomController>& aTarget,
     CancelableBlockState* aBlock) {
   INPQ_LOG("scheduling main thread timeout for target %p\n", aTarget.get());
   aBlock->StartContentResponseTimer();
   RefPtr<Runnable> timeoutTask = NewRunnableMethod<uint64_t>(
       "layers::InputQueue::MainThreadTimeout", this,
       &InputQueue::MainThreadTimeout, aBlock->GetBlockId());
-  int32_t timeout = StaticPrefs::APZContentResponseTimeout();
+  int32_t timeout = StaticPrefs::apz_content_response_timeout();
   if (timeout == 0) {
     // If the timeout is zero, treat it as a request to ignore any main
     // thread confirmation and unconditionally use fallback behaviour for
     // when a timeout is reached. This codepath is used by tests that
     // want to exercise the fallback behaviour.
     // To ensure the fallback behaviour is used unconditionally, the timeout
     // is run right away instead of using PostDelayedTask(). However,
     // we can't run it right here, because MainThreadTimeout() expects that

--- a/gfx/layers/apz/src/SimpleVelocityTracker.cpp
+++ b/gfx/layers/apz/src/SimpleVelocityTracker.cpp
@@ -81,51 +81,53 @@ float SimpleVelocityTracker::HandleDynam
   return velocity;
 }
 
 Maybe<float> SimpleVelocityTracker::ComputeVelocity(uint32_t aTimestampMs) {
   float velocity = 0;
   int count = 0;
   for (const auto& e : mVelocityQueue) {
     uint32_t timeDelta = (aTimestampMs - e.first);
-    if (timeDelta < StaticPrefs::APZVelocityRelevanceTime()) {
+    if (timeDelta < StaticPrefs::apz_velocity_relevance_time_ms()) {
       count++;
       velocity += e.second;
     }
   }
   mVelocityQueue.Clear();
   if (count > 1) {
     velocity /= count;
   }
   return Some(velocity);
 }
 
 void SimpleVelocityTracker::Clear() { mVelocityQueue.Clear(); }
 
 void SimpleVelocityTracker::AddVelocityToQueue(uint32_t aTimestampMs,
                                                float aVelocity) {
   mVelocityQueue.AppendElement(std::make_pair(aTimestampMs, aVelocity));
-  if (mVelocityQueue.Length() > StaticPrefs::APZMaxVelocityQueueSize()) {
+  if (mVelocityQueue.Length() > StaticPrefs::apz_max_velocity_queue_size()) {
     mVelocityQueue.RemoveElementAt(0);
   }
 }
 
 float SimpleVelocityTracker::ApplyFlingCurveToVelocity(float aVelocity) const {
   float newVelocity = aVelocity;
-  if (StaticPrefs::APZMaxVelocity() > 0.0f) {
+  if (StaticPrefs::apz_max_velocity_inches_per_ms() > 0.0f) {
     bool velocityIsNegative = (newVelocity < 0);
     newVelocity = fabs(newVelocity);
 
-    float maxVelocity = mAxis->ToLocalVelocity(StaticPrefs::APZMaxVelocity());
+    float maxVelocity =
+        mAxis->ToLocalVelocity(StaticPrefs::apz_max_velocity_inches_per_ms());
     newVelocity = std::min(newVelocity, maxVelocity);
 
-    if (StaticPrefs::APZCurveThreshold() > 0.0f &&
-        StaticPrefs::APZCurveThreshold() < StaticPrefs::APZMaxVelocity()) {
-      float curveThreshold =
-          mAxis->ToLocalVelocity(StaticPrefs::APZCurveThreshold());
+    if (StaticPrefs::apz_fling_curve_threshold_inches_per_ms() > 0.0f &&
+        StaticPrefs::apz_fling_curve_threshold_inches_per_ms() <
+            StaticPrefs::apz_max_velocity_inches_per_ms()) {
+      float curveThreshold = mAxis->ToLocalVelocity(
+          StaticPrefs::apz_fling_curve_threshold_inches_per_ms());
       if (newVelocity > curveThreshold) {
         // here, 0 < curveThreshold < newVelocity <= maxVelocity, so we apply
         // the curve
         float scale = maxVelocity - curveThreshold;
         float funcInput = (newVelocity - curveThreshold) / scale;
         float funcOutput = gVelocityCurveFunction->GetValue(
             funcInput, ComputedTimingFunction::BeforeFlag::Unset);
         float curvedVelocity = (funcOutput * scale) + curveThreshold;

--- a/gfx/layers/apz/test/gtest/TestPinching.cpp
+++ b/gfx/layers/apz/test/gtest/TestPinching.cpp
@@ -156,47 +156,50 @@ class APZCPinchLockingTester : public AP
         CreatePinchGestureInput(PinchGestureInput::PINCHGESTURE_START, mFocus,
                                 mSpan, mSpan, mcc->Time()),
         nullptr);
     mcc->AdvanceBy(TimeDuration::FromMilliseconds(51));
   }
 
   void twoFingerPan() {
     ScreenCoord panDistance =
-        StaticPrefs::APZPinchLockScrollLockThreshold() * 1.2 * tm->GetDPI();
+        StaticPrefs::apz_pinch_lock_scroll_lock_threshold() * 1.2 *
+        tm->GetDPI();
 
     mFocus = ScreenIntPoint((int)(mFocus.x + panDistance), (int)(mFocus.y));
 
     apzc->ReceiveInputEvent(
         CreatePinchGestureInput(PinchGestureInput::PINCHGESTURE_SCALE, mFocus,
                                 mSpan, mSpan, mcc->Time()),
         nullptr);
     mcc->AdvanceBy(TimeDuration::FromMilliseconds(51));
   }
 
   void twoFingerZoom() {
     float pinchDistance =
-        StaticPrefs::APZPinchLockSpanBreakoutThreshold() * 1.2 * tm->GetDPI();
+        StaticPrefs::apz_pinch_lock_span_breakout_threshold() * 1.2 *
+        tm->GetDPI();
 
     float newSpan = mSpan + pinchDistance;
 
     apzc->ReceiveInputEvent(
         CreatePinchGestureInput(PinchGestureInput::PINCHGESTURE_SCALE, mFocus,
                                 newSpan, mSpan, mcc->Time()),
         nullptr);
     mcc->AdvanceBy(TimeDuration::FromMilliseconds(51));
     mSpan = newSpan;
   }
 
   bool isPinchLockActive() {
     FrameMetrics originalMetrics = apzc->GetFrameMetrics();
 
     // Send a small scale input to the APZC
     float pinchDistance =
-        StaticPrefs::APZPinchLockSpanBreakoutThreshold() * 0.8 * tm->GetDPI();
+        StaticPrefs::apz_pinch_lock_span_breakout_threshold() * 0.8 *
+        tm->GetDPI();
     apzc->ReceiveInputEvent(
         CreatePinchGestureInput(PinchGestureInput::PINCHGESTURE_SCALE, mFocus,
                                 mSpan + pinchDistance, mSpan, mcc->Time()),
         nullptr);
 
     FrameMetrics result = apzc->GetFrameMetrics();
     bool lockActive =
         originalMetrics.GetZoom() == result.GetZoom() &&
@@ -247,32 +250,32 @@ TEST_F(APZCPinchGestureDetectorTester,
 
 TEST_F(APZCPinchGestureDetectorTester,
        Pinch_UseGestureDetector_TouchActionNone_NoAPZZoom) {
   SCOPED_GFX_PREF_BOOL("layout.css.touch_action.enabled", true);
   SCOPED_GFX_PREF_BOOL("apz.allow_zooming", false);
 
   // Since we are preventing the pinch action via touch-action we should not be
   // sending the pinch gesture notifications that would normally be sent when
-  // APZAllowZooming is false.
+  // apz_allow_zooming is false.
   EXPECT_CALL(*mcc, NotifyPinchGesture(_, _, _, _)).Times(0);
   nsTArray<uint32_t> behaviors = {mozilla::layers::AllowedTouchBehavior::NONE,
                                   mozilla::layers::AllowedTouchBehavior::NONE};
   DoPinchTest(false, &behaviors);
 }
 
 TEST_F(APZCPinchGestureDetectorTester, Pinch_PreventDefault) {
   DoPinchWithPreventDefaultTest();
 }
 
 TEST_F(APZCPinchGestureDetectorTester, Pinch_PreventDefault_NoAPZZoom) {
   SCOPED_GFX_PREF_BOOL("apz.allow_zooming", false);
 
   // Since we are preventing the pinch action we should not be sending the pinch
-  // gesture notifications that would normally be sent when APZAllowZooming is
+  // gesture notifications that would normally be sent when apz_allow_zooming is
   // false.
   EXPECT_CALL(*mcc, NotifyPinchGesture(_, _, _, _)).Times(0);
 
   DoPinchWithPreventDefaultTest();
 }
 
 TEST_F(APZCPinchGestureDetectorTester, Panning_TwoFingerFling_ZoomDisabled) {
   SCOPED_GFX_PREF_FLOAT("apz.fling_min_velocity_threshold", 0.0f);
@@ -430,21 +433,21 @@ TEST_F(APZCPinchTester, Panning_Beyond_L
 }
 
 TEST_F(APZCPinchGestureDetectorTester, Pinch_APZZoom_Disabled) {
   SCOPED_GFX_PREF_BOOL("apz.allow_zooming", false);
 
   FrameMetrics originalMetrics = GetPinchableFrameMetrics();
   apzc->SetFrameMetrics(originalMetrics);
 
-  // When APZAllowZooming is false, the ZoomConstraintsClient produces
+  // When apz_allow_zooming is false, the ZoomConstraintsClient produces
   // ZoomConstraints with mAllowZoom set to false.
   MakeApzcUnzoomable();
 
-  // With APZAllowZooming false, we expect the NotifyPinchGesture function to
+  // With apz_allow_zooming false, we expect the NotifyPinchGesture function to
   // get called as the pinch progresses, but the metrics shouldn't change.
   EXPECT_CALL(*mcc,
               NotifyPinchGesture(PinchGestureInput::PINCHGESTURE_START,
                                  apzc->GetGuid(), LayoutDeviceCoord(0), _))
       .Times(1);
   EXPECT_CALL(*mcc, NotifyPinchGesture(PinchGestureInput::PINCHGESTURE_SCALE,
                                        apzc->GetGuid(), _, _))
       .Times(AtLeast(1));
@@ -469,21 +472,21 @@ TEST_F(APZCPinchGestureDetectorTester, P
 
 TEST_F(APZCPinchGestureDetectorTester, Pinch_NoSpan) {
   SCOPED_GFX_PREF_BOOL("apz.allow_zooming", false);
   SCOPED_GFX_PREF_BOOL("layout.css.touch_action.enabled", false);
 
   FrameMetrics originalMetrics = GetPinchableFrameMetrics();
   apzc->SetFrameMetrics(originalMetrics);
 
-  // When APZAllowZooming is false, the ZoomConstraintsClient produces
+  // When apz_allow_zooming is false, the ZoomConstraintsClient produces
   // ZoomConstraints with mAllowZoom set to false.
   MakeApzcUnzoomable();
 
-  // With APZAllowZooming false, we expect the NotifyPinchGesture function to
+  // With apz_allow_zooming false, we expect the NotifyPinchGesture function to
   // get called as the pinch progresses, but the metrics shouldn't change.
   EXPECT_CALL(*mcc,
               NotifyPinchGesture(PinchGestureInput::PINCHGESTURE_START,
                                  apzc->GetGuid(), LayoutDeviceCoord(0), _))
       .Times(1);
   EXPECT_CALL(*mcc, NotifyPinchGesture(PinchGestureInput::PINCHGESTURE_SCALE,
                                        apzc->GetGuid(), _, _))
       .Times(AtLeast(1));

--- a/gfx/layers/apz/test/gtest/TestScrollHandoff.cpp
+++ b/gfx/layers/apz/test/gtest/TestScrollHandoff.cpp
@@ -519,16 +519,17 @@ TEST_F(APZScrollHandoffTester, Scrollgra
 
   // Check that the parent and child have scrolled as much as we expect.
   EXPECT_EQ(20, rootApzc->GetFrameMetrics().GetScrollOffset().y);
   EXPECT_EQ(15, childApzc->GetFrameMetrics().GetScrollOffset().y);
 }
 
 TEST_F(APZScrollHandoffTester, ScrollgrabFling) {
   SCOPED_GFX_PREF_FLOAT("apz.fling_min_velocity_threshold", 0.0f);
+
   // Set up the layer tree
   CreateScrollgrabLayerTree();
 
   RefPtr<TestAsyncPanZoomController> childApzc = ApzcOf(layers[1]);
 
   // Pan on the child, not enough to fully scroll the scrollgrab parent.
   Pan(childApzc, 80, 70);
 

--- a/gfx/layers/apz/util/CheckerboardReportService.cpp
+++ b/gfx/layers/apz/util/CheckerboardReportService.cpp
@@ -186,17 +186,17 @@ void CheckerboardReportService::GetRepor
     nsTArray<dom::CheckerboardReport>& aOutReports) {
   RefPtr<mozilla::layers::CheckerboardEventStorage> instance =
       mozilla::layers::CheckerboardEventStorage::GetInstance();
   MOZ_ASSERT(instance);
   instance->GetReports(aOutReports);
 }
 
 bool CheckerboardReportService::IsRecordingEnabled() const {
-  return StaticPrefs::APZRecordCheckerboarding();
+  return StaticPrefs::apz_record_checkerboarding();
 }
 
 void CheckerboardReportService::SetRecordingEnabled(bool aEnabled) {
   Preferences::SetBool("apz.record_checkerboarding", aEnabled);
 }
 
 void CheckerboardReportService::FlushActiveReports() {
   MOZ_ASSERT(XRE_IsParentProcess());

--- a/gfx/layers/client/TiledContentClient.cpp
+++ b/gfx/layers/client/TiledContentClient.cpp
@@ -224,19 +224,19 @@ bool SharedFrameMetricsHelper::AboutToCh
                     aContentMetrics.GetScrollOffset();
   painted.Inflate(CSSMargin::FromAppUnits(nsMargin(1, 1, 1, 1)));
 
   // Inflate the rect by the danger zone. See the description of the danger zone
   // prefs in AsyncPanZoomController.cpp for an explanation of this.
   CSSRect showing =
       CSSRect(aCompositorMetrics.GetScrollOffset(),
               aCompositorMetrics.CalculateBoundedCompositedSizeInCssPixels());
-  showing.Inflate(
-      LayerSize(StaticPrefs::APZDangerZoneX(), StaticPrefs::APZDangerZoneY()) /
-      aCompositorMetrics.LayersPixelsPerCSSPixel());
+  showing.Inflate(LayerSize(StaticPrefs::apz_danger_zone_x(),
+                            StaticPrefs::apz_danger_zone_y()) /
+                  aCompositorMetrics.LayersPixelsPerCSSPixel());
 
   // Clamp both rects to the scrollable rect, because having either of those
   // exceed the scrollable rect doesn't make sense, and could lead to false
   // positives.
   painted = painted.Intersect(aContentMetrics.GetScrollableRect());
   showing = showing.Intersect(aContentMetrics.GetScrollableRect());
 
   if (!painted.Contains(showing)) {

--- a/gfx/layers/composite/AsyncCompositionManager.cpp
+++ b/gfx/layers/composite/AsyncCompositionManager.cpp
@@ -1482,18 +1482,18 @@ bool AsyncCompositionManager::TransformS
 #if defined(MOZ_WIDGET_ANDROID)
 void AsyncCompositionManager::SetFixedLayerMargins(ScreenIntCoord aTop,
                                                    ScreenIntCoord aBottom) {
   mFixedLayerMargins.top = aTop;
   mFixedLayerMargins.bottom = aBottom;
 }
 ScreenMargin AsyncCompositionManager::GetFixedLayerMargins() const {
   ScreenMargin result = mFixedLayerMargins;
-  if (StaticPrefs::APZFixedMarginOverrideEnabled()) {
-    result.top = StaticPrefs::APZFixedMarginOverrideTop();
-    result.bottom = StaticPrefs::APZFixedMarginOverrideBottom();
+  if (StaticPrefs::apz_fixed_margin_override_enabled()) {
+    result.top = StaticPrefs::apz_fixed_margin_override_top();
+    result.bottom = StaticPrefs::apz_fixed_margin_override_bottom();
   }
   return result;
 }
 #endif  // defined(MOZ_WIDGET_ANDROID)
 
 }  // namespace layers
 }  // namespace mozilla

--- a/gfx/layers/composite/ContainerLayerComposite.cpp
+++ b/gfx/layers/composite/ContainerLayerComposite.cpp
@@ -504,17 +504,17 @@ void RenderLayers(ContainerT* aContainer
               asyncTransform * aContainer->GetEffectiveTransform());
           asyncTransform =
               sampler->GetCurrentAsyncTransformWithOverscroll(wrapper)
                   .ToUnknownMatrix() *
               asyncTransform;
         }
       }
 
-      if (StaticPrefs::APZMinimap()) {
+      if (StaticPrefs::apz_minimap_enabled()) {
         RenderMinimap(aContainer, sampler, aManager, aClipRect, layer);
       }
     }
 
     // invariant: our GL context should be current here, I don't think we can
     // assert it though
   }
 }

--- a/gfx/thebes/gfxPlatform.cpp
+++ b/gfx/thebes/gfxPlatform.cpp
@@ -3227,17 +3227,17 @@ void gfxPlatform::GetApzSupportInfo(mozi
     aObj.DefineProperty("ApzTouchInput", 1);
   }
 
   if (SupportsApzDragInput()) {
     aObj.DefineProperty("ApzDragInput", 1);
   }
 
   if (SupportsApzKeyboardInput() &&
-      !StaticPrefs::AccessibilityBrowseWithCaret()) {
+      !StaticPrefs::accessibility_browsewithcaret()) {
     aObj.DefineProperty("ApzKeyboardInput", 1);
   }
 
   if (SupportsApzAutoscrolling()) {
     aObj.DefineProperty("ApzAutoscrollInput", 1);
   }
 }
 
@@ -3472,25 +3472,25 @@ void gfxPlatform::ImportGPUDeviceData(
   gfxConfig::ImportChange(Feature::ADVANCED_LAYERS, aData.advancedLayers());
 }
 
 bool gfxPlatform::SupportsApzTouchInput() const {
   return dom::TouchEvent::PrefEnabled(nullptr);
 }
 
 bool gfxPlatform::SupportsApzDragInput() const {
-  return StaticPrefs::APZDragEnabled();
+  return StaticPrefs::apz_drag_enabled();
 }
 
 bool gfxPlatform::SupportsApzKeyboardInput() const {
-  return StaticPrefs::APZKeyboardEnabled();
+  return StaticPrefs::apz_keyboard_enabled();
 }
 
 bool gfxPlatform::SupportsApzAutoscrolling() const {
-  return StaticPrefs::APZAutoscrollEnabled();
+  return StaticPrefs::apz_autoscroll_enabled();
 }
 
 void gfxPlatform::InitOpenGLConfig() {
 #ifdef XP_WIN
   // Don't enable by default on Windows, since it could show up in about:support
   // even though it'll never get used. Only attempt if user enables the pref
   if (!Preferences::GetBool("layers.prefer-opengl")) {
     return;

--- a/layout/base/PresShell.cpp
+++ b/layout/base/PresShell.cpp
@@ -6003,17 +6003,17 @@ void PresShell::Paint(nsView* aViewToPai
   NS_ASSERTION(aViewToPaint, "null view");
 
   MOZ_ASSERT(!mApproximateFrameVisibilityVisited, "Should have been cleared");
 
   if (!mIsActive) {
     return;
   }
 
-  if (StaticPrefs::APZKeyboardEnabled()) {
+  if (StaticPrefs::apz_keyboard_enabled()) {
     // Update the focus target for async keyboard scrolling. This will be
     // forwarded to APZ by nsDisplayList::PaintRoot. We need to to do this
     // before we enter the paint phase because dispatching eVoid events can
     // cause layout to happen.
     mAPZFocusTarget = FocusTarget(this, mAPZFocusSequenceNumber);
   }
 
   nsPresContext* presContext = GetPresContext();

--- a/layout/base/ZoomConstraintsClient.cpp
+++ b/layout/base/ZoomConstraintsClient.cpp
@@ -168,17 +168,17 @@ void ZoomConstraintsClient::ScreenSizeCh
 }
 
 static mozilla::layers::ZoomConstraints ComputeZoomConstraintsFromViewportInfo(
     const nsViewportInfo& aViewportInfo, Document* aDocument) {
   mozilla::layers::ZoomConstraints constraints;
   constraints.mAllowZoom = aViewportInfo.IsZoomAllowed() &&
                            nsLayoutUtils::AllowZoomingForDocument(aDocument);
   constraints.mAllowDoubleTapZoom =
-      constraints.mAllowZoom && StaticPrefs::APZAllowDoubleTapZooming();
+      constraints.mAllowZoom && StaticPrefs::apz_allow_double_tap_zooming();
   if (constraints.mAllowZoom) {
     constraints.mMinZoom.scale = aViewportInfo.GetMinZoom().scale;
     constraints.mMaxZoom.scale = aViewportInfo.GetMaxZoom().scale;
   } else {
     constraints.mMinZoom.scale = aViewportInfo.GetDefaultZoom().scale;
     constraints.mMaxZoom.scale = aViewportInfo.GetDefaultZoom().scale;
   }
   return constraints;

--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -753,17 +753,17 @@ bool nsLayoutUtils::AsyncPanZoomEnabled(
   return widget->AsyncPanZoomEnabled();
 }
 
 bool nsLayoutUtils::AllowZoomingForDocument(
     const mozilla::dom::Document* aDocument) {
   // True if we allow zooming for all documents on this platform, or if we are
   // in RDM and handling meta viewports, which force zoom under some
   // circumstances.
-  return StaticPrefs::APZAllowZooming() ||
+  return StaticPrefs::apz_allow_zooming() ||
          (aDocument && aDocument->InRDMPane() &&
           nsLayoutUtils::ShouldHandleMetaViewport(aDocument));
 }
 
 float nsLayoutUtils::GetCurrentAPZResolutionScale(PresShell* aPresShell) {
   return aPresShell ? aPresShell->GetCumulativeNonRootScaleResolution() : 1.0;
 }
 
@@ -1045,17 +1045,17 @@ bool nsLayoutUtils::ShouldDisableApzForE
         return true;
       }
     }
   }
 
   if (!doc) {
     return false;
   }
-  return StaticPrefs::APZDisableForScrollLinkedEffects() &&
+  return StaticPrefs::apz_disable_for_scroll_linked_effects() &&
          doc->HasScrollLinkedEffect();
 }
 
 static bool GetDisplayPortData(
     nsIContent* aContent, DisplayPortPropertyData** aOutRectData,
     DisplayPortMarginsPropertyData** aOutMarginsData) {
   MOZ_ASSERT(aOutRectData && aOutMarginsData);
 
@@ -9248,17 +9248,17 @@ ScrollMetadata nsLayoutUtils::ComputeScr
   frameBounds.Deflate(boundMargins);
 
   metrics.SetCompositionBounds(frameBounds);
 
   metrics.SetRootCompositionSize(nsLayoutUtils::CalculateRootCompositionSize(
       aScrollFrame ? aScrollFrame : aForFrame, isRootContentDocRootScrollFrame,
       metrics));
 
-  if (StaticPrefs::APZPrintTree() || StaticPrefs::apz_test_logging_enabled()) {
+  if (StaticPrefs::apz_printtree() || StaticPrefs::apz_test_logging_enabled()) {
     if (nsIContent* content =
             frameForCompositionBoundsCalculation->GetContent()) {
       nsAutoString contentDescription;
       if (content->IsElement()) {
         content->AsElement()->Describe(contentDescription);
       } else {
         contentDescription.AssignLiteral("(not an element)");
       }

--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -1861,17 +1861,17 @@ void nsRefreshDriver::Tick(VsyncId aId, 
   mTickVsyncId = aId;
   mTickVsyncTime = aNowTime;
 
   gfxPlatform::GetPlatform()->SchedulePaintIfDeviceReset();
 
   // We want to process any pending APZ metrics ahead of their positions
   // in the queue. This will prevent us from spending precious time
   // painting a stale displayport.
-  if (StaticPrefs::APZPeekMessages()) {
+  if (StaticPrefs::apz_peek_messages_enabled()) {
     nsLayoutUtils::UpdateDisplayPortMarginsFromPendingMessages();
   }
 
   AutoTArray<nsCOMPtr<nsIRunnable>, 16> earlyRunners;
   earlyRunners.SwapElements(mEarlyRunners);
   for (auto& runner : earlyRunners) {
     runner->Run();
   }

--- a/layout/generic/ScrollVelocityQueue.cpp
+++ b/layout/generic/ScrollVelocityQueue.cpp
@@ -19,17 +19,17 @@ void ScrollVelocityQueue::Sample(const n
   maxVelocity = nsPresContext::CSSPixelsToAppUnits(maxVelocity);
   int maxOffset = maxVelocity * flingSensitivity;
   TimeStamp currentRefreshTime =
       mPresContext->RefreshDriver()->MostRecentRefresh();
   if (mSampleTime.IsNull()) {
     mAccumulator = nsPoint();
   } else {
     uint32_t durationMs = (currentRefreshTime - mSampleTime).ToMilliseconds();
-    if (durationMs > StaticPrefs::APZVelocityRelevanceTime()) {
+    if (durationMs > StaticPrefs::apz_velocity_relevance_time_ms()) {
       mAccumulator = nsPoint();
       mQueue.Clear();
     } else if (durationMs == 0) {
       mAccumulator += aScrollPosition - mLastPosition;
     } else {
       nsPoint velocity = mAccumulator * 1000 / durationMs;
       velocity.Clamp(maxVelocity);
       mQueue.AppendElement(std::make_pair(durationMs, velocity));
@@ -49,17 +49,17 @@ void ScrollVelocityQueue::TrimQueue() {
   }
 
   TimeStamp currentRefreshTime =
       mPresContext->RefreshDriver()->MostRecentRefresh();
   nsPoint velocity;
   uint32_t timeDelta = (currentRefreshTime - mSampleTime).ToMilliseconds();
   for (int i = mQueue.Length() - 1; i >= 0; i--) {
     timeDelta += mQueue[i].first;
-    if (timeDelta >= StaticPrefs::APZVelocityRelevanceTime()) {
+    if (timeDelta >= StaticPrefs::apz_velocity_relevance_time_ms()) {
       // The rest of the samples have expired and should be dropped
       for (; i >= 0; i--) {
         mQueue.RemoveElementAt(0);
       }
     }
   }
 }
 

--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -2462,17 +2462,17 @@ void ScrollFrameHelper::MarkRecentlyScro
   // reset the timer.
   ResetDisplayPortExpiryTimer();
 }
 
 void ScrollFrameHelper::ResetDisplayPortExpiryTimer() {
   if (mDisplayPortExpiryTimer) {
     mDisplayPortExpiryTimer->InitWithNamedFuncCallback(
         RemoveDisplayPortCallback, this,
-        StaticPrefs::APZDisplayPortExpiryTime(), nsITimer::TYPE_ONE_SHOT,
+        StaticPrefs::apz_displayport_expiry_ms(), nsITimer::TYPE_ONE_SHOT,
         "ScrollFrameHelper::ResetDisplayPortExpiryTimer");
   }
 }
 
 bool ScrollFrameHelper::AllowDisplayPortExpiration() {
   if (IsAlwaysActive()) {
     return false;
   }
@@ -2482,17 +2482,17 @@ bool ScrollFrameHelper::AllowDisplayPort
   return true;
 }
 
 void ScrollFrameHelper::TriggerDisplayPortExpiration() {
   if (!AllowDisplayPortExpiration()) {
     return;
   }
 
-  if (!StaticPrefs::APZDisplayPortExpiryTime()) {
+  if (!StaticPrefs::apz_displayport_expiry_ms()) {
     // a zero time disables the expiry
     return;
   }
 
   if (!mDisplayPortExpiryTimer) {
     mDisplayPortExpiryTimer = NS_NewTimer();
   }
   ResetDisplayPortExpiryTimer();
@@ -2798,17 +2798,17 @@ void ScrollFrameHelper::ScrollToImpl(nsP
   }
 
   ScrollVisual();
   mAnchor.UserScrolled();
 
   bool schedulePaint = true;
   if (nsLayoutUtils::AsyncPanZoomEnabled(mOuter) &&
       !nsLayoutUtils::ShouldDisableApzForElement(content) &&
-      StaticPrefs::APZPaintSkipping()) {
+      StaticPrefs::apz_paint_skipping_enabled()) {
     // If APZ is enabled with paint-skipping, there are certain conditions in
     // which we can skip paints:
     // 1) If APZ triggered this scroll, and the tile-aligned displayport is
     //    unchanged.
     // 2) If non-APZ triggered this scroll, but we can handle it by just asking
     //    APZ to update the scroll position. Again we make this conditional on
     //    the tile-aligned displayport being unchanged.
     // We do the displayport check first since it's common to all scenarios,
@@ -2833,17 +2833,17 @@ void ScrollFrameHelper::ScrollToImpl(nsP
         mScrollableByAPZ, HasPluginFrames(), HasPerspective(),
         HasBgAttachmentLocal(), mHasOutOfFlowContentInsideFilter);
     if (usingDisplayPort && displayPort.IsEqualEdges(oldDisplayPort) &&
         !HasPerspective() && !HasBgAttachmentLocal() &&
         !mHasOutOfFlowContentInsideFilter) {
       bool haveScrollLinkedEffects =
           content->GetComposedDoc()->HasScrollLinkedEffect();
       bool apzDisabled = haveScrollLinkedEffects &&
-                         StaticPrefs::APZDisableForScrollLinkedEffects();
+                         StaticPrefs::apz_disable_for_scroll_linked_effects();
       if (!apzDisabled && !HasPluginFrames()) {
         if (LastScrollOrigin() == nsGkAtoms::apz) {
           schedulePaint = false;
           PAINT_SKIP_LOG("Skipping due to APZ scroll\n");
         } else if (mScrollableByAPZ) {
           nsIWidget* widget = presContext->GetNearestWidget();
           LayerManager* manager = widget ? widget->GetLayerManager() : nullptr;
           if (manager) {

--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -1140,17 +1140,17 @@ void nsDisplayListBuilder::AutoCurrentAc
 /* static */
 nsRect nsDisplayListBuilder::OutOfFlowDisplayData::ComputeVisibleRectForFrame(
     nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
     const nsRect& aVisibleRect, const nsRect& aDirtyRect,
     nsRect* aOutDirtyRect) {
   nsRect visible = aVisibleRect;
   nsRect dirtyRectRelativeToDirtyFrame = aDirtyRect;
 
-  if (StaticPrefs::APZAllowZooming() &&
+  if (StaticPrefs::apz_allow_zooming() &&
       nsLayoutUtils::IsFixedPosFrameInDisplayPort(aFrame) &&
       aBuilder->IsPaintingToWindow()) {
     dirtyRectRelativeToDirtyFrame =
         nsRect(nsPoint(0, 0), aFrame->GetParent()->GetSize());
 
     // If there's a visual viewport size set, restrict the amount of the
     // fixed-position element we paint to the visual viewport. (In general
     // the fixed-position element can be as large as the layout viewport,

--- a/modules/libpref/init/StaticPrefList.h
+++ b/modules/libpref/init/StaticPrefList.h
@@ -55,17 +55,17 @@
 //   many VarCaches that should be atomic are not, in particular because
 //   Atomic<float> is not available, alas.)
 //
 // Definitions of VarCache prefs in this file has the following form.
 //
 //   VARCACHE_PREF(
 //     <update-policy>,
 //     <pref-name-string>,
-//     <pref-name-id>,
+//      <pref-name-id>,  // indented one space to align with <pref-name-string>
 //     <cpp-type>, <default-value>
 //   )
 //
 // - <update-policy> is one of the following:
 //
 //   * Live: Evaluate the pref and set callback so it stays current/live. This
 //     is the normal policy.
 //
@@ -112,600 +112,584 @@
 
 //---------------------------------------------------------------------------
 // Prefs starting with "accessibility."
 //---------------------------------------------------------------------------
 
 VARCACHE_PREF(
   Live,
   "accessibility.monoaudio.enable",
-  accessibility_monoaudio_enable,
+   accessibility_monoaudio_enable,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "accessibility.browsewithcaret",
-  AccessibilityBrowseWithCaret,
+   accessibility_browsewithcaret,
   RelaxedAtomicBool, false
 )
 
 //---------------------------------------------------------------------------
 // Prefs starting with "apz."
 // The apz prefs are explained in AsyncPanZoomController.cpp
 //---------------------------------------------------------------------------
 
 VARCACHE_PREF(
   Live,
   "apz.allow_double_tap_zooming",
-  APZAllowDoubleTapZooming,
+   apz_allow_double_tap_zooming,
   RelaxedAtomicBool, true
 )
 
 VARCACHE_PREF(
   Live,
   "apz.allow_immediate_handoff",
-  APZAllowImmediateHandoff,
+   apz_allow_immediate_handoff,
   RelaxedAtomicBool, true
 )
 
 VARCACHE_PREF(
   Live,
   "apz.allow_zooming",
-  APZAllowZooming,
+   apz_allow_zooming,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.android.chrome_fling_physics.enabled",
-  APZUseChromeFlingPhysics,
+   apz_android_chrome_fling_physics_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.android.chrome_fling_physics.friction",
-  APZChromeFlingPhysicsFriction,
+   apz_android_chrome_fling_physics_friction,
   AtomicFloat, 0.015f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.android.chrome_fling_physics.inflexion",
-  APZChromeFlingPhysicsInflexion,
+   apz_android_chrome_fling_physics_inflexion,
   AtomicFloat, 0.35f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.android.chrome_fling_physics.stop_threshold",
-  APZChromeFlingPhysicsStopThreshold,
+   apz_android_chrome_fling_physics_stop_threshold,
   AtomicFloat, 0.1f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.autoscroll.enabled",
-  APZAutoscrollEnabled,
+   apz_autoscroll_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.axis_lock.breakout_angle",
-  APZAxisBreakoutAngle,
+   apz_axis_lock_breakout_angle,
   AtomicFloat, float(M_PI / 8.0) /* 22.5 degrees */
 )
 
 VARCACHE_PREF(
   Live,
   "apz.axis_lock.breakout_threshold",
-  APZAxisBreakoutThreshold,
+   apz_axis_lock_breakout_threshold,
   AtomicFloat, 1.0f / 32.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.axis_lock.direct_pan_angle",
-  APZAllowedDirectPanAngle,
+   apz_axis_lock_direct_pan_angle,
   AtomicFloat, float(M_PI / 3.0) /* 60 degrees */
 )
 
 VARCACHE_PREF(
   Live,
   "apz.axis_lock.lock_angle",
-  APZAxisLockAngle,
+   apz_axis_lock_lock_angle,
   AtomicFloat, float(M_PI / 6.0) /* 30 degrees */
 )
 
 VARCACHE_PREF(
   Live,
   "apz.axis_lock.mode",
-  APZAxisLockMode,
+   apz_axis_lock_mode,
   RelaxedAtomicInt32, 0
 )
 
 VARCACHE_PREF(
   Live,
   "apz.content_response_timeout",
-  APZContentResponseTimeout,
+   apz_content_response_timeout,
   RelaxedAtomicInt32, 400
 )
 
 VARCACHE_PREF(
   Live,
   "apz.danger_zone_x",
-  APZDangerZoneX,
+   apz_danger_zone_x,
   RelaxedAtomicInt32, 50
 )
 
 VARCACHE_PREF(
   Live,
   "apz.danger_zone_y",
-  APZDangerZoneY,
+   apz_danger_zone_y,
   RelaxedAtomicInt32, 100
 )
 
 VARCACHE_PREF(
   Live,
   "apz.disable_for_scroll_linked_effects",
-  APZDisableForScrollLinkedEffects,
+   apz_disable_for_scroll_linked_effects,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.displayport_expiry_ms",
-  APZDisplayPortExpiryTime,
+   apz_displayport_expiry_ms,
   RelaxedAtomicUint32, 15000
 )
 
 VARCACHE_PREF(
   Live,
   "apz.drag.enabled",
-  APZDragEnabled,
+   apz_drag_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.drag.initial.enabled",
-  APZDragInitiationEnabled,
+   apz_drag_initial_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.drag.touch.enabled",
-  APZTouchDragEnabled,
+   apz_touch_drag_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.enlarge_displayport_when_clipped",
-  APZEnlargeDisplayPortWhenClipped,
+   apz_enlarge_displayport_when_clipped,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fixed-margin-override.enabled",
-  APZFixedMarginOverrideEnabled,
+   apz_fixed_margin_override_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fixed-margin-override.bottom",
-  APZFixedMarginOverrideBottom,
+   apz_fixed_margin_override_bottom,
   RelaxedAtomicInt32, 0
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fixed-margin-override.top",
-  APZFixedMarginOverrideTop,
+   apz_fixed_margin_override_top,
   RelaxedAtomicInt32, 0
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_accel_base_mult",
-  APZFlingAccelBaseMultiplier,
+   apz_fling_accel_base_mult,
   AtomicFloat, 1.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_accel_interval_ms",
-  APZFlingAccelInterval,
+   apz_fling_accel_interval_ms,
   RelaxedAtomicInt32, 500
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_accel_supplemental_mult",
-  APZFlingAccelSupplementalMultiplier,
+   apz_fling_accel_supplemental_mult,
   AtomicFloat, 1.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_accel_min_velocity",
-  APZFlingAccelMinVelocity,
+   apz_fling_accel_min_velocity,
   AtomicFloat, 1.5f
 )
 
 VARCACHE_PREF(
   Once,
   "apz.fling_curve_function_x1",
-  APZCurveFunctionX1,
+   apz_fling_curve_function_x1,
   float, 0.0f
 )
 
 VARCACHE_PREF(
   Once,
   "apz.fling_curve_function_x2",
-  APZCurveFunctionX2,
+   apz_fling_curve_function_x2,
   float, 1.0f
 )
 
 VARCACHE_PREF(
   Once,
   "apz.fling_curve_function_y1",
-  APZCurveFunctionY1,
+   apz_fling_curve_function_y1,
   float, 0.0f
 )
 
 VARCACHE_PREF(
   Once,
   "apz.fling_curve_function_y2",
-  APZCurveFunctionY2,
+   apz_fling_curve_function_y2,
   float, 1.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_curve_threshold_inches_per_ms",
-  APZCurveThreshold,
+   apz_fling_curve_threshold_inches_per_ms,
   AtomicFloat, -1.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_friction",
-  APZFlingFriction,
+   apz_fling_friction,
   AtomicFloat, 0.002f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_min_velocity_threshold",
-  APZFlingMinVelocityThreshold,
+   apz_fling_min_velocity_threshold,
   AtomicFloat, 0.5f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_stop_on_tap_threshold",
-  APZFlingStopOnTapThreshold,
+   apz_fling_stop_on_tap_threshold,
   AtomicFloat, 0.05f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.fling_stopped_threshold",
-  APZFlingStoppedThreshold,
+   apz_fling_stopped_threshold,
   AtomicFloat, 0.01f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.frame_delay.enabled",
-  APZFrameDelayEnabled,
+   apz_frame_delay_enabled,
   RelaxedAtomicBool, false
 )
 
 #ifdef MOZ_WIDGET_GTK
 VARCACHE_PREF(
   Live,
   "apz.gtk.kinetic_scroll.enabled",
-  APZGTKKineticScrollEnabled,
+   apz_gtk_kinetic_scroll_enabled,
   RelaxedAtomicBool, false
 )
 #endif
 
 #if !defined(MOZ_WIDGET_ANDROID)
 # define PREF_VALUE true
 #else
 # define PREF_VALUE false
 #endif
 VARCACHE_PREF(
   Once,
   "apz.keyboard.enabled",
-  APZKeyboardEnabled,
+   apz_keyboard_enabled,
   bool, PREF_VALUE
 )
 #undef PREF_VALUE
 
 VARCACHE_PREF(
   Live,
   "apz.keyboard.passive-listeners",
-  APZKeyboardPassiveListeners,
+   apz_keyboard_passive_listeners,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.max_tap_time",
-  APZMaxTapTime,
+   apz_max_tap_time,
   RelaxedAtomicInt32, 300
 )
 
 VARCACHE_PREF(
   Live,
   "apz.max_velocity_inches_per_ms",
-  APZMaxVelocity,
+   apz_max_velocity_inches_per_ms,
   AtomicFloat, -1.0f
 )
 
 VARCACHE_PREF(
   Once,
   "apz.max_velocity_queue_size",
-  APZMaxVelocityQueueSize,
+   apz_max_velocity_queue_size,
   uint32_t, 5
 )
 
 VARCACHE_PREF(
   Live,
   "apz.min_skate_speed",
-  APZMinSkateSpeed,
+   apz_min_skate_speed,
   AtomicFloat, 1.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.minimap.enabled",
-  APZMinimap,
+   apz_minimap_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.one_touch_pinch.enabled",
-  APZOneTouchPinchEnabled,
+   apz_one_touch_pinch_enabled,
   RelaxedAtomicBool, true
 )
 
 VARCACHE_PREF(
   Live,
   "apz.overscroll.enabled",
-  APZOverscrollEnabled,
+   apz_overscroll_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.overscroll.min_pan_distance_ratio",
-  APZMinPanDistanceRatio,
+   apz_overscroll_min_pan_distance_ratio,
   AtomicFloat, 1.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.overscroll.spring_stiffness",
-  APZOverscrollSpringStiffness,
+   apz_overscroll_spring_stiffness,
   AtomicFloat, 0.001f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.overscroll.stop_distance_threshold",
-  APZOverscrollStopDistanceThreshold,
+   apz_overscroll_stop_distance_threshold,
   AtomicFloat, 5.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.paint_skipping.enabled",
-  APZPaintSkipping,
+   apz_paint_skipping_enabled,
   RelaxedAtomicBool, true
 )
 
 VARCACHE_PREF(
   Live,
   "apz.peek_messages.enabled",
-  APZPeekMessages,
+   apz_peek_messages_enabled,
   RelaxedAtomicBool, true
 )
 
 VARCACHE_PREF(
   Live,
   "apz.pinch_lock.mode",
-  APZPinchLockMode,
+   apz_pinch_lock_mode,
   RelaxedAtomicInt32, 1
 )
 
 VARCACHE_PREF(
   Live,
   "apz.pinch_lock.scroll_lock_threshold",
-  APZPinchLockScrollLockThreshold,
+   apz_pinch_lock_scroll_lock_threshold,
   AtomicFloat, 1.0f / 32.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.pinch_lock.span_breakout_threshold",
-  APZPinchLockSpanBreakoutThreshold,
+   apz_pinch_lock_span_breakout_threshold,
   AtomicFloat, 1.0f / 32.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.pinch_lock.span_lock_threshold",
-  APZPinchLockSpanLockThreshold,
+   apz_pinch_lock_span_lock_threshold,
   AtomicFloat, 1.0f / 32.0f
 )
 
 VARCACHE_PREF(
   Once,
   "apz.pinch_lock.buffer_max_age",
-  APZPinchLockBufferMaxAge,
+   apz_pinch_lock_buffer_max_age,
   int32_t, 50 // milliseconds
 )
 
 VARCACHE_PREF(
   Live,
   "apz.popups.enabled",
-  APZPopupsEnabled,
+   apz_popups_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.printtree",
-  APZPrintTree,
+   apz_printtree,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.record_checkerboarding",
-  APZRecordCheckerboarding,
+   apz_record_checkerboarding,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.second_tap_tolerance",
-  APZSecondTapTolerance,
+   apz_second_tap_tolerance,
   AtomicFloat, 0.5f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.test.fails_with_native_injection",
-  APZTestFailsWithNativeInjection,
+   apz_test_fails_with_native_injection,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.test.logging_enabled",
-  apz_test_logging_enabled,
+   apz_test_logging_enabled,
   RelaxedAtomicBool, false
 )
 
 VARCACHE_PREF(
   Live,
   "apz.touch_move_tolerance",
-  APZTouchMoveTolerance,
+   apz_touch_move_tolerance,
   AtomicFloat, 0.1f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.touch_start_tolerance",
-  APZTouchStartTolerance,
+   apz_touch_start_tolerance,
   AtomicFloat, 1.0f/4.5f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.velocity_bias",
-  APZVelocityBias,
+   apz_velocity_bias,
   AtomicFloat, 0.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.velocity_relevance_time_ms",
-  APZVelocityRelevanceTime,
+   apz_velocity_relevance_time_ms,
   RelaxedAtomicUint32, 150
 )
 
 VARCACHE_PREF(
   Live,
   "apz.x_skate_highmem_adjust",
-  APZXSkateHighMemAdjust,
+   apz_x_skate_highmem_adjust,
   AtomicFloat, 0.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.x_skate_size_multiplier",
-  APZXSkateSizeMultiplier,
+   apz_x_skate_size_multiplier,
   AtomicFloat, 1.5f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.x_stationary_size_multiplier",
-  APZXStationarySizeMultiplier,
+   apz_x_stationary_size_multiplier,
   AtomicFloat, 3.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.y_skate_highmem_adjust",
-  APZYSkateHighMemAdjust,
+   apz_y_skate_highmem_adjust,
   AtomicFloat, 0.0f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.y_skate_size_multiplier",
-  APZYSkateSizeMultiplier,
+   apz_y_skate_size_multiplier,
   AtomicFloat, 2.5f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.y_stationary_size_multiplier",
-  APZYStationarySizeMultiplier,
+   apz_y_stationary_size_multiplier,
   AtomicFloat, 3.5f
 )
 
 VARCACHE_PREF(
   Live,
   "apz.zoom_animation_duration_ms",
-  APZZoomAnimationDuration,
+   apz_zoom_animation_duration_ms,
   RelaxedAtomicInt32, 250
 )
 
 VARCACHE_PREF(
   Live,
   "apz.scale_repaint_delay_ms",
-  APZScaleRepaintDelay,
+   apz_scale_repaint_delay_ms,
   RelaxedAtomicInt32, 500
 )
 
 VARCACHE_PREF(
   Live,
   "apz.relative-update.enabled",
-  APZRelativeUpdate,
-  RelaxedAtomicBool, false
-)
-
-VARCACHE_PREF(
-  Live,
-  "full-screen-api.mouse-event-allow-left-button-only",
-  full_screen_api_mouse_event_allow_left_button_only,
-  bool, true
-)
-
-// When this pref is set, parent documents may consider child iframes've loaded
-// while they are still loading
-VARCACHE_PREF(
-  Live,
-  "dom.cross_origin_iframes_loaded_in_background",
-   dom_cross_origin_iframes_loaded_in_background,
-  bool, false
+   apz_relative_update_enabled,
+  RelaxedAtomicBool, false
 )
 
 //---------------------------------------------------------------------------
 // Prefs starting with "beacon."
 //---------------------------------------------------------------------------
 
 // Is support for Navigator.sendBeacon enabled?
 VARCACHE_PREF(
@@ -2643,16 +2627,25 @@ VARCACHE_PREF(
 // Is support for XMLDocument.load enabled?
 VARCACHE_PREF(
   Live,
   "dom.xmldocument.load.enabled",
   dom_xmldocument_load_enabled,
   bool, false
 )
 
+// When this pref is set, parent documents may consider child iframes have
+// loaded while they are still loading.
+VARCACHE_PREF(
+  Live,
+  "dom.cross_origin_iframes_loaded_in_background",
+   dom_cross_origin_iframes_loaded_in_background,
+  bool, false
+)
+
 // Is support for Navigator.geolocation enabled?
 VARCACHE_PREF(
   Live,
   "geo.enabled",
   geo_enabled,
   bool, true
 )
 
@@ -2731,16 +2724,23 @@ VARCACHE_PREF(
 
 VARCACHE_PREF(
   Live,
   "full-screen-api.allow-trusted-requests-only",
   full_screen_api_allow_trusted_requests_only,
   bool, true
 )
 
+VARCACHE_PREF(
+  Live,
+  "full-screen-api.mouse-event-allow-left-button-only",
+   full_screen_api_mouse_event_allow_left_button_only,
+  bool, true
+)
+
 //---------------------------------------------------------------------------
 // Prefs starting with "fuzzing.". It's important that these can only be
 // checked in fuzzing builds (when FUZZING is defined), otherwise you could
 // enable the fuzzing stuff on your regular build which would be bad :)
 //---------------------------------------------------------------------------
 
 #ifdef FUZZING
 VARCACHE_PREF(

--- a/widget/cocoa/nsChildView.mm
+++ b/widget/cocoa/nsChildView.mm
@@ -3570,17 +3570,17 @@ NSEvent* gLastDragMouseDownEvent = nil;
 - (void)magnifyWithEvent:(NSEvent*)anEvent {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   if (!mGeckoChild) {
     return;
   }
 
   // FIXME: bug 1525793 -- this may need to handle zooming or not on a per-document basis.
-  if (StaticPrefs::APZAllowZooming()) {
+  if (StaticPrefs::apz_allow_zooming()) {
     NSPoint locationInWindow = nsCocoaUtils::EventLocationForWindow(anEvent, [self window]);
     ScreenPoint position =
         ViewAs<ScreenPixel>([self convertWindowCoordinatesRoundDown:locationInWindow],
                             PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent);
     ExternalPoint screenOffset =
         ViewAs<ExternalPixel>(mGeckoChild->WidgetToScreenOffset(),
                               PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent);
 

--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -3052,17 +3052,17 @@ void nsWindow::OnScrollEvent(GdkEventScr
       // the GDK_SCROLL_SMOOTH direction on XInput2 and Wayland devices.
       mLastScrollEventTime = aEvent->time;
 
       // Special handling for touchpads to support flings
       // (also known as kinetic/inertial/momentum scrolling)
       GdkDevice* device = gdk_event_get_source_device((GdkEvent*)aEvent);
       GdkInputSource source = gdk_device_get_source(device);
       if (source == GDK_SOURCE_TOUCHSCREEN || source == GDK_SOURCE_TOUCHPAD) {
-        if (StaticPrefs::APZGTKKineticScrollEnabled() &&
+        if (StaticPrefs::apz_gtk_kinetic_scroll_enabled() &&
             gtk_check_version(3, 20, 0) == nullptr) {
           static auto sGdkEventIsScrollStopEvent =
               (gboolean(*)(const GdkEvent*))dlsym(
                   RTLD_DEFAULT, "gdk_event_is_scroll_stop_event");
 
           LOG(("[%d] pan smooth event dx=%f dy=%f inprogress=%d\n",
                aEvent->time, aEvent->delta_x, aEvent->delta_y, mPanInProgress));
           PanGestureInput::PanGestureType eventType =

--- a/widget/nsBaseWidget.cpp
+++ b/widget/nsBaseWidget.cpp
@@ -854,17 +854,17 @@ bool nsBaseWidget::ComputeShouldAccelera
          WidgetTypeSupportsAcceleration();
 }
 
 bool nsBaseWidget::UseAPZ() {
   return (gfxPlatform::AsyncPanZoomEnabled() &&
           (WindowType() == eWindowType_toplevel ||
            WindowType() == eWindowType_child ||
            (WindowType() == eWindowType_popup && HasRemoteContent() &&
-            StaticPrefs::APZPopupsEnabled())));
+            StaticPrefs::apz_popups_enabled())));
 }
 
 bool nsBaseWidget::AllowWebRenderForThisWindow() {
   return WindowType() == eWindowType_toplevel ||
          WindowType() == eWindowType_child ||
          WindowType() == eWindowType_dialog ||
          (WindowType() == eWindowType_popup && HasRemoteContent());
 }
@@ -888,17 +888,17 @@ void nsBaseWidget::ConfigureAPZCTreeMana
   ConfigureAPZControllerThread();
 
   float dpi = GetDPI();
   // On Android the main thread is not the controller thread
   APZThreadUtils::RunOnControllerThread(
       NewRunnableMethod<float>("layers::IAPZCTreeManager::SetDPI", mAPZC,
                                &IAPZCTreeManager::SetDPI, dpi));
 
-  if (StaticPrefs::APZKeyboardEnabled()) {
+  if (StaticPrefs::apz_keyboard_enabled()) {
     KeyboardMap map = nsXBLWindowKeyHandler::CollectKeyboardShortcuts();
     // On Android the main thread is not the controller thread
     APZThreadUtils::RunOnControllerThread(NewRunnableMethod<KeyboardMap>(
         "layers::IAPZCTreeManager::SetKeyboardMap", mAPZC,
         &IAPZCTreeManager::SetKeyboardMap, map));
   }
 
   RefPtr<IAPZCTreeManager> treeManager = mAPZC;  // for capture by the lambdas

--- a/widget/windows/nsWindowBase.cpp
+++ b/widget/windows/nsWindowBase.cpp
@@ -128,17 +128,18 @@ void nsWindowBase::ChangedDPI() {
 }
 
 nsresult nsWindowBase::SynthesizeNativeTouchPoint(
     uint32_t aPointerId, nsIWidget::TouchPointerState aPointerState,
     LayoutDeviceIntPoint aPoint, double aPointerPressure,
     uint32_t aPointerOrientation, nsIObserver* aObserver) {
   AutoObserverNotifier notifier(aObserver, "touchpoint");
 
-  if (StaticPrefs::APZTestFailsWithNativeInjection() || !InitTouchInjection()) {
+  if (StaticPrefs::apz_test_fails_with_native_injection() ||
+      !InitTouchInjection()) {
     // If we don't have touch injection from the OS, or if we are running a test
     // that cannot properly inject events to satisfy the OS requirements (see
     // bug 1313170)  we can just fake it and synthesize the events from here.
     MOZ_ASSERT(NS_IsMainThread());
     if (aPointerState == TOUCH_HOVER) {
       return NS_ERROR_UNEXPECTED;
     }