From c1fd24b30bb775b5071bc3743566e98892878418 Mon Sep 17 00:00:00 2001
From: Kartikaya Gupta <kgupta@mozilla.com>
Date: Thu, 28 Apr 2016 11:29:35 -0400
Subject: [PATCH] Bug 1268523 - Avoid leaking tasks when they are posted to a
 destroyed APZC instance. r=botond

MozReview-Commit-ID: 9hAkzCVg7el

--HG--
extra : rebase_source : 8f9a71ec1354fe57c1401655b81bcb178eb6d1c2
---
 gfx/layers/apz/src/AsyncPanZoomController.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index cef0f6c53767..8c6b03b4f7e8 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -3853,11 +3853,14 @@ AsyncPanZoomController::GetZoomConstraints() const
 
 void AsyncPanZoomController::PostDelayedTask(already_AddRefed<Runnable> aTask, int aDelayMs) {
   APZThreadUtils::AssertOnControllerThread();
+  RefPtr<Runnable> task = aTask;
   RefPtr<GeckoContentController> controller = GetGeckoContentController();
   if (controller) {
-    controller->PostDelayedTask(Move(aTask), aDelayMs);
+    controller->PostDelayedTask(task.forget(), aDelayMs);
   }
-  // XXX khuey what is supposed to happen if there's no controller? We were leaking tasks ...
+  // If there is no controller, that means this APZC has been destroyed, and
+  // we probably don't need to run the task. It will get destroyed when the
+  // RefPtr goes out of scope.
 }
 
 bool AsyncPanZoomController::Matches(const ScrollableLayerGuid& aGuid)