v8binding: Makes ToV8(window) work without a frame.

third_party/WebKit/Source/core/frame/DOMWindow.cpp

Index: third_party/WebKit/Source/core/frame/DOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/DOMWindow.cpp b/third_party/WebKit/Source/core/frame/DOMWindow.cpp
index 831460a2baca733a3cd921b9204c230d89fc9d23..57f5bc8b0f3ec392836f949e7e984c6a37bd844d 100644
--- a/third_party/WebKit/Source/core/frame/DOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/DOMWindow.cpp
@@ -5,6 +5,8 @@
 #include "core/frame/DOMWindow.h"
 
 #include <memory>
+
+#include "bindings/core/v8/WindowProxyManager.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/dom/SecurityContext.h"
@@ -29,7 +31,10 @@
 
 namespace blink {
 
-DOMWindow::DOMWindow(Frame& frame) : m_frame(frame), m_windowIsClosing(false) {}
+DOMWindow::DOMWindow(Frame& frame)
+    : m_frame(frame),
+      m_windowProxyManager(frame.getWindowProxyManager()),
+      m_windowIsClosing(false) {}
 
 DOMWindow::~DOMWindow() {
   // The frame must be disconnected before finalization.
@@ -415,6 +420,10 @@ void DOMWindow::focus(ExecutionContext* context) {
   page->focusController().focusDocumentView(frame(), true /* notifyEmbedder */);
 }
 
+v8::Local<v8::Object> DOMWindow::globalProxy(DOMWrapperWorld& world) {
+  return m_windowProxyManager->windowProxy(world)->globalProxyIfNotDetached();

[haraken, 2017/04/07 10:08:58]

So, are you planning to change this in the future to return a valid global proxy
even after the frame gets detached?

[Yuki, 2017/04/07 10:30:44]

Yes, I hope that I can make it someday.

+}
+
 InputDeviceCapabilitiesConstants* DOMWindow::getInputDeviceCapabilities() {
   if (!m_inputCapabilities)
     m_inputCapabilities = new InputDeviceCapabilitiesConstants;
@@ -423,6 +432,7 @@ InputDeviceCapabilitiesConstants* DOMWindow::getInputDeviceCapabilities() {
 
 DEFINE_TRACE(DOMWindow) {
   visitor->trace(m_frame);
+  visitor->trace(m_windowProxyManager);
   visitor->trace(m_inputCapabilities);
   visitor->trace(m_location);
   EventTargetWithInlineData::trace(visitor);