Implement PaintWorkletGlobalScope#registerPaint() for the CSS Paint API

third_party/WebKit/Source/modules/csspaint/WindowPaintWorklet.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/csspaint/WindowPaintWorklet.h"
 
+#include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "modules/csspaint/PaintWorklet.h"
 
 namespace blink {
 
 WindowPaintWorklet::WindowPaintWorklet(LocalDOMWindow& window)
     : DOMWindowProperty(window.frame())
 {
 }
@@ skipping 22 matching lines @@
     return from(toLocalDOMWindow(window)).paintWorklet(executionContext);
 }
 
 PaintWorklet* WindowPaintWorklet::paintWorklet(ExecutionContext* executionContext) const
 {
     if (!m_paintWorklet && frame())
         m_paintWorklet = PaintWorklet::create(frame(), executionContext);
     return m_paintWorklet.get();
 }
 
+void WindowPaintWorklet::willDetachGlobalObjectFromFrame()

[ikilpatrick, 2016/03/30 19:12:50]

I'm not sure if the dispose call on the scriptController should be in this or
willDestroyGlobalObjectInFrame.

I believe it should be this as the window's perContextData gets disposed of
here:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

This is called from document->detach as few lines above.

Thoughts?

+{
+    if (m_paintWorklet)
+        m_paintWorklet->workletGlobalScope()->scriptController()->dispose();
+    DOMWindowProperty::willDetachGlobalObjectFromFrame();
+}
+
 DEFINE_TRACE(WindowPaintWorklet)
 {
     visitor->trace(m_paintWorklet);
     WillBeHeapSupplement<LocalDOMWindow>::trace(visitor);
     DOMWindowProperty::trace(visitor);
 }
 
 } // namespace blink