Special-case LocalDOMWindow for same-origin access in bindings.

third_party/WebKit/Source/modules/webaudio/WindowAudioWorklet.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/webaudio/WindowAudioWorklet.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
-#include "modules/webaudio/AudioWorklet.h"
 
 namespace blink {
 
-WindowAudioWorklet::WindowAudioWorklet(LocalDOMWindow& window)
-    : ContextLifecycleObserver(window.frame()->document()) {}
-
-const char* WindowAudioWorklet::supplementName() {
-  return "WindowAudioWorklet";
-}
-
-WindowAudioWorklet& WindowAudioWorklet::from(LocalDOMWindow& window) {
-  WindowAudioWorklet* supplement = static_cast<WindowAudioWorklet*>(
-      Supplement<LocalDOMWindow>::from(window, supplementName()));
-  if (!supplement) {
-    supplement = new WindowAudioWorklet(window);
-    provideTo(window, supplementName(), supplement);
-  }
-  return *supplement;
-}
-
-Worklet* WindowAudioWorklet::audioWorklet(DOMWindow& window) {
+AudioWorklet* WindowAudioWorklet::audioWorklet(LocalDOMWindow& window) {
   if (!window.frame())
     return nullptr;
-  return from(toLocalDOMWindow(window)).audioWorklet(toLocalDOMWindow(window));
-}
-
-AudioWorklet* WindowAudioWorklet::audioWorklet(LocalDOMWindow& window) {
-  if (!m_audioWorklet && getExecutionContext()) {
-    DCHECK(window.frame());
-    m_audioWorklet = AudioWorklet::create(window.frame());
-  }
-  return m_audioWorklet.get();
+  return from(window).m_audioWorklet.get();
 }
 
 // Break the following cycle when the context gets detached.
 // Otherwise, the worklet object will leak.
+// TODO(dcheng): Why isn't this just all on the Oilpan heap?
 //
 // window => window.audioWorklet
 // => WindowAudioWorklet
 // => AudioWorklet  <--- break this reference
 // => ThreadedWorkletMessagingProxy
 // => Document
 // => ... => window
 void WindowAudioWorklet::contextDestroyed(ExecutionContext*) {
   m_audioWorklet = nullptr;
 }
 
 DEFINE_TRACE(WindowAudioWorklet) {
   visitor->trace(m_audioWorklet);
   Supplement<LocalDOMWindow>::trace(visitor);
   ContextLifecycleObserver::trace(visitor);
 }
 
+WindowAudioWorklet& WindowAudioWorklet::from(LocalDOMWindow& window) {
+  WindowAudioWorklet* supplement = static_cast<WindowAudioWorklet*>(
+      Supplement<LocalDOMWindow>::from(window, supplementName()));
+  if (!supplement) {
+    supplement = new WindowAudioWorklet(window);
+    provideTo(window, supplementName(), supplement);
+  }
+  return *supplement;
+}
+
+WindowAudioWorklet::WindowAudioWorklet(LocalDOMWindow& window)
+    : ContextLifecycleObserver(window.frame()->document()),
+      m_audioWorklet(AudioWorklet::create(window.frame())) {}
+
+const char* WindowAudioWorklet::supplementName() {
+  return "WindowAudioWorklet";
+}
+
 }  // namespace blink