Move VTTRegion Timers to TaskRunnerTimer

third_party/WebKit/Source/core/html/track/vtt/VTTRegion.cpp

 /*
  * Copyright (C) 2013 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 18 matching lines @@
  */
 
 #include "core/html/track/vtt/VTTRegion.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/ClientRect.h"
 #include "core/dom/DOMTokenList.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/TaskRunnerHelper.h"
 #include "core/html/HTMLDivElement.h"
 #include "core/html/track/vtt/VTTParser.h"
 #include "core/html/track/vtt/VTTScanner.h"
 #include "wtf/MathExtras.h"
 
 #define VTT_LOG_LEVEL 3
 
 namespace blink {
 
 // The following values default values are defined within the WebVTT Regions
@@ skipping 34 matching lines @@
 }
 
 VTTRegion::VTTRegion()
     : m_id(emptyString),
       m_width(defaultWidth),
       m_lines(defaultHeightInLines),
       m_regionAnchor(FloatPoint(defaultAnchorPointX, defaultAnchorPointY)),
       m_viewportAnchor(FloatPoint(defaultAnchorPointX, defaultAnchorPointY)),
       m_scroll(defaultScroll),
       m_currentTop(0),
-      m_scrollTimer(this, &VTTRegion::scrollTimerFired) {}
+      m_scrollTimer(
+          TaskRunnerHelper::get(TaskType::UnspecedTimer, (Document*)nullptr),

[maksims (do not use this acc), 2017/02/14 08:28:58]

What about this solution? I've tested it and it seemed to work.

[foolip, 2017/02/14 13:37:09]

The cast is a little suspicious. Does just nullptr not work, and is the value
here not actually used for anything?

[maksims (do not use this acc), 2017/02/16 06:44:05]

Check TaskRunnerHelper::get(). It's an overloaded function with different
parameters. Nullptr leads to ambiguous call. But if that is casted to a document
or anything else, then task runner is taken from the Platform::current().

[foolip, 2017/02/16 07:46:09]

From cs.chromium.org at a glance, I can't find any other call sites where the
second argument is always null, probably because that's a roundabout way of
writing Platform::current()->currentThread()->getWebTaskRunner().

Can you use Platform::current()->currentThread()->getWebTaskRunner() instead?

Somehow getting the right task queue from the document in which the region will
be rendered, something like PS1, feels like the other best option, but that
might require some refactoring to not have to do the std::unique_ptr thing.

[maksims (do not use this acc), 2017/02/16 09:16:22]

Done.

+          this,
+          &VTTRegion::scrollTimerFired) {}
 
 VTTRegion::~VTTRegion() {}
 
 void VTTRegion::setId(const String& id) {
   m_id = id;
 }
 
 void VTTRegion::setWidth(double value, ExceptionState& exceptionState) {
   if (isNonPercentage(value, "width", exceptionState))
     return;
@@ skipping 305 matching lines @@
   stopTimer();
   displayLastVTTCueBox();
 }
 
 DEFINE_TRACE(VTTRegion) {
   visitor->trace(m_cueContainer);
   visitor->trace(m_regionDisplayTree);
 }
 
 }  // namespace blink