Fix memory leak with ScriptedIdleTaskController

If there is an untriggered idle task when the document is gone, it introduces memory leak because IdleRequestCallbackWrapper keeps a reference to the ScriptedIdleTaskController, making it live longer than the document. This patch fixes the issue by letting IdleRequestCallbackWrapper store a WeakPersistent instead. BUG=595155 Review-Url: https://codereview.chromium.org/2618893002 Cr-Commit-Position: refs/heads/master@{#441929}

Fix memory leak with ScriptedIdleTaskController
If there is an untriggered idle task when the document is gone, it introduces memory leak because IdleRequestCallbackWrapper keeps a reference to the ScriptedIdleTaskController, making it live longer than the document. This patch fixes the issue by letting IdleRequestCallbackWrapper store a WeakPersistent instead. BUG=595155 Review-Url: https://codereview.chromium.org/2618893002 Cr-Commit-Position: refs/heads/master@{#441929}
114c62b9 · xiaochengh · Commit bot · c771336b · 114c62b9 · 114c62b9
Commit 114c62b9 authored Jan 06, 2017 by xiaochengh Committed by Commit bot Jan 06, 2017
2 changed files
--- a/third_party/WebKit/LayoutTests/idle-callback/untriggered-do-not-leak.html
+++ b/third_party/WebKit/LayoutTests/idle-callback/untriggered-do-not-leak.html
+<!doctype html>
+<script src="../resources/testharness.js"></script>
+<script src="../resources/testharnessreport.js"></script>
+<script>
+test(
+  () => requestIdleCallback(() =>
+      assert_unreached('Should not trigger the idle task during the test.')),
+  'Untriggered idle task does not introduce memory leak.');
+
+test(
+  () => {
+    const handle = requestIdleCallback(() =>
+        assert_unreached('Should not trigger the idle task during the test.'));
+    cancelIdleCallback(handle);
+  }, 'Canceled idle task does not introduce memory leak.');
+</script>
--- 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