Bug 1298638 - Check if mAPZEventState is null. r=kats

MozReview-Commit-ID: E6fx5zVUzIU

gfx/layers/apz/util/ChromeProcessController.cpp

@@ -171,6 +171,10 @@ ChromeProcessController::HandleTap(TapType aType,
     return;
   }
 
+  if (!mAPZEventState) {
+    return;
+  }
+
   nsCOMPtr<nsIPresShell> presShell = GetPresShell();
   if (!presShell) {
     return;
@@ -217,6 +221,10 @@ ChromeProcessController::NotifyAPZStateChange(const ScrollableLayerGuid& aGuid,
     return;
   }
 
+  if (!mAPZEventState) {
+    return;
+  }
+
   mAPZEventState->ProcessAPZStateChange(GetRootDocument(), aGuid.mScrollId, aChange, aArg);
 }