Remove DOMWindowProperty from WindowPaintWorklet

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

Index: third_party/WebKit/Source/modules/csspaint/WindowPaintWorklet.cpp
diff --git a/third_party/WebKit/Source/modules/csspaint/WindowPaintWorklet.cpp b/third_party/WebKit/Source/modules/csspaint/WindowPaintWorklet.cpp
index d3dbc993cbbd5af58f45d073e372810aa6f4b919..379c4526dbfee84c2f3461490fe9320d16edb9b4 100644
--- a/third_party/WebKit/Source/modules/csspaint/WindowPaintWorklet.cpp
+++ b/third_party/WebKit/Source/modules/csspaint/WindowPaintWorklet.cpp
@@ -11,7 +11,7 @@
 namespace blink {
 
 WindowPaintWorklet::WindowPaintWorklet(LocalDOMWindow& window)
-    : DOMWindowProperty(window.frame()) {}
+    : Supplement<LocalDOMWindow>(window) {}
 
 const char* WindowPaintWorklet::supplementName() {
   return "WindowPaintWorklet";
@@ -34,15 +34,14 @@ Worklet* WindowPaintWorklet::paintWorklet(DOMWindow& window) {
 }
 
 PaintWorklet* WindowPaintWorklet::paintWorklet() {
-  if (!m_paintWorklet && frame())
-    m_paintWorklet = PaintWorklet::create(frame());
+  if (!m_paintWorklet && host() && host()->frame())

[sof, 2017/01/13 07:29:13]

we really have to support operating in a host()-free setting? (if we can
maintain the invariant that host() can never be null for supplements, that'd be
simpler.)

+    m_paintWorklet = PaintWorklet::create(host()->frame());
   return m_paintWorklet.get();
 }
 
 DEFINE_TRACE(WindowPaintWorklet) {
   visitor->trace(m_paintWorklet);
   Supplement<LocalDOMWindow>::trace(visitor);
-  DOMWindowProperty::trace(visitor);
 }
 
 }  // namespace blink