Bug 1015331 - Do not leak Task object created during fling handoff. r=kats

gfx/layers/apz/src/AsyncPanZoomController.cpp

@@ -1728,6 +1728,7 @@ bool AsyncPanZoomController::SampleContentTransformForFrame(const TimeStamp& aSa
 
   for (uint32_t i = 0; i < deferredTasks.length(); ++i) {
     deferredTasks[i]->Run();
+    delete deferredTasks[i];
   }
 
   // Cancel the mAsyncScrollTimeoutTask because we will fire a