Replace Document::postTask with WebTaskRunner::postTask

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

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 03a65cf6a6ec13f79de3710a15377b2db0ef2274..e6169ac4cc664b80c49ae1e7938272b5309e8216 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -386,6 +386,9 @@ static bool s_threadedParsingEnabledForTesting = true;
 
 // This doesn't work with non-Document ExecutionContext.
 static void runAutofocusTask(ExecutionContext* context) {
+  if (!context)
+    return;
+
   Document* document = toDocument(context);
   if (Element* element = document->autofocusElement()) {
     document->setAutofocusElement(0);
@@ -5717,15 +5720,18 @@ static void runAddConsoleMessageTask(MessageSource source,
                                      MessageLevel level,
                                      const String& message,
                                      ExecutionContext* context) {
-  context->addConsoleMessage(ConsoleMessage::create(source, level, message));
+  if (context)
+    context->addConsoleMessage(ConsoleMessage::create(source, level, message));
 }
 
 void Document::addConsoleMessage(ConsoleMessage* consoleMessage) {
   if (!isContextThread()) {
-    postTask(TaskType::Unthrottled, BLINK_FROM_HERE,
-             createCrossThreadTask(
-                 &runAddConsoleMessageTask, consoleMessage->source(),
-                 consoleMessage->level(), consoleMessage->message()));
+    TaskRunnerHelper::get(TaskType::Unthrottled, this)
+        ->postTask(
+            BLINK_FROM_HERE,
+            crossThreadBind(&runAddConsoleMessageTask, consoleMessage->source(),
+                            consoleMessage->level(), consoleMessage->message(),
+                            wrapCrossThreadWeakPersistent(this)));

[haraken, 2017/02/13 06:43:51]

I guess we should use a strong Persistent here because the console message
should be printed regardless of the document is gone or not.

[yuryu, 2017/02/13 09:14:04]

Done.

     return;
   }
 
@@ -6312,8 +6318,9 @@ void Document::setAutofocusElement(Element* element) {
   m_hasAutofocused = true;
   DCHECK(!m_autofocusElement);
   m_autofocusElement = element;
-  postTask(TaskType::UserInteraction, BLINK_FROM_HERE,
-           createSameThreadTask(&runAutofocusTask));
+  TaskRunnerHelper::get(TaskType::UserInteraction, this)
+      ->postTask(BLINK_FROM_HERE,
+                 WTF::bind(&runAutofocusTask, wrapWeakPersistent(this)));

[haraken, 2017/02/13 06:43:52]

Ditto.

[tzik, 2017/02/13 06:56:33]

I think this should be weak, since focusing an element doesn't make sense on a
detached document.

[haraken, 2017/02/13 06:58:35]

Then we should explicitly check if the document has been detached or not. Note
that a weak persistent handle is cleared when a GC is eventually triggered not
when the document gets detached.

[tzik, 2017/02/13 08:58:53]

We don't need the check, since it's done in Element::focus().
The Persistent here extends the lifetime of Document slightly for an effective
nop.

[yuryu, 2017/02/13 09:14:04]

Do you think it's good to add a comment about it? If it's confusing.

[yuryu, 2017/02/13 09:21:15]

Done.

 }
 
 Element* Document::activeElement() const {