Bug 957790 - Remove a no-longer-used pref to disable async zooming in the APZ. r=jimm

gfx/layers/ipc/AsyncPanZoomController.cpp

@@ -241,11 +241,6 @@ static int gAsyncScrollThrottleTime = 100;
  */
 static int gAsyncScrollTimeout = 300;
 
-/**
- * Temporary pref for disabling zoom in metrofx on aurora.
- */
-static bool gAsyncZoomDisabled = false;
-
 /**
  * Pref that enables integration with the Metro "cross-slide" gesture.
  */
@@ -375,7 +370,6 @@ AsyncPanZoomController::InitializeGlobalState()
   Preferences::AddFloatVarCache(&gYStationarySizeMultiplier, "apz.y_stationary_size_multiplier", gYStationarySizeMultiplier);
   Preferences::AddIntVarCache(&gAsyncScrollThrottleTime, "apz.asyncscroll.throttle", gAsyncScrollThrottleTime);
   Preferences::AddIntVarCache(&gAsyncScrollTimeout, "apz.asyncscroll.timeout", gAsyncScrollTimeout);
-  Preferences::AddBoolVarCache(&gAsyncZoomDisabled, "apz.asynczoom.disabled", gAsyncZoomDisabled);
   Preferences::AddBoolVarCache(&gCrossSlideEnabled, "apz.cross_slide.enabled", gCrossSlideEnabled);
   Preferences::AddIntVarCache(&gAxisLockMode, "apz.axis_lock_mode", gAxisLockMode);
   gUseProgressiveTilePainting = gfxPlatform::UseProgressiveTilePainting();
@@ -417,9 +411,6 @@ AsyncPanZoomController::AsyncPanZoomController(uint64_t aLayersId,
   if (aGestures == USE_GESTURE_DETECTOR) {
     mGestureEventListener = new GestureEventListener(this);
   }
-  if (gAsyncZoomDisabled) {
-    mZoomConstraints.mAllowZoom = false;
-  }
 }
 
 AsyncPanZoomController::~AsyncPanZoomController() {
@@ -1652,9 +1643,6 @@ void AsyncPanZoomController::TimeoutTouchListeners() {
 }
 
 void AsyncPanZoomController::UpdateZoomConstraints(const ZoomConstraints& aConstraints) {
-  if (gAsyncZoomDisabled) {
-    return;
-  }
   mZoomConstraints.mAllowZoom = aConstraints.mAllowZoom;
   mZoomConstraints.mMinZoom = (MIN_ZOOM > aConstraints.mMinZoom ? MIN_ZOOM : aConstraints.mMinZoom);
   mZoomConstraints.mMaxZoom = (MAX_ZOOM > aConstraints.mMaxZoom ? aConstraints.mMaxZoom : MAX_ZOOM);