Fix memory leak with ScriptedIdleTaskController

third_party/WebKit/Source/core/dom/ScriptedIdleTaskController.cpp

Index: third_party/WebKit/Source/core/dom/ScriptedIdleTaskController.cpp
diff --git a/third_party/WebKit/Source/core/dom/ScriptedIdleTaskController.cpp b/third_party/WebKit/Source/core/dom/ScriptedIdleTaskController.cpp
index 263766a0c308be166693dd4591c354f6c0ca793f..7f31434373b002fe1f89719c97311b065d3f7302 100644
--- a/third_party/WebKit/Source/core/dom/ScriptedIdleTaskController.cpp
+++ b/third_party/WebKit/Source/core/dom/ScriptedIdleTaskController.cpp
@@ -62,7 +62,7 @@ class IdleRequestCallbackWrapper
       : m_id(id), m_controller(controller) {}
 
   ScriptedIdleTaskController::CallbackId m_id;
-  Persistent<ScriptedIdleTaskController> m_controller;
+  WeakPersistent<ScriptedIdleTaskController> m_controller;
 };
 
 }  // namespace internal