GuestView: Move lifetime management out of content

content/browser/web_contents/web_contents_view_guest.cc

Index: content/browser/web_contents/web_contents_view_guest.cc
diff --git a/content/browser/web_contents/web_contents_view_guest.cc b/content/browser/web_contents/web_contents_view_guest.cc
index efa92bdc0ee4ae7421bf6e52c1c51dc31371b905..17a5c484ef6a3416420157ee9064a12cc3e91434 100644
--- a/content/browser/web_contents/web_contents_view_guest.cc
+++ b/content/browser/web_contents/web_contents_view_guest.cc
@@ -60,7 +60,7 @@ gfx::NativeWindow WebContentsViewGuest::GetTopLevelNativeWindow() const {
   return guest_->embedder_web_contents()->GetTopLevelNativeWindow();
 }
 
-void WebContentsViewGuest::OnGuestInitialized(WebContentsView* parent_view) {
+void WebContentsViewGuest::OnGuestAttached(WebContentsView* parent_view) {
 #if defined(USE_AURA)
   // In aura, ScreenPositionClient doesn't work properly if we do
   // not have the native view associated with this WebContentsViewGuest in the
@@ -71,6 +71,13 @@ void WebContentsViewGuest::OnGuestInitialized(WebContentsView* parent_view) {
 #endif  // defined(USE_AURA)
 }
 
+void WebContentsViewGuest::OnGuestDetached(WebContentsView* old_parent_view) {
+#if defined(USE_AURA)
+  old_parent_view->GetNativeView()->RemoveChild(
+      platform_view_->GetNativeView());
+#endif  // defined(USE_AURA)
+}
+
 ContextMenuParams WebContentsViewGuest::ConvertContextMenuParams(
     const ContextMenuParams& params) const {
   // We need to add |offset| of the guest from the embedder to position the
@@ -143,12 +150,9 @@ RenderWidgetHostViewBase* WebContentsViewGuest::CreateViewForWidget(
   RenderWidgetHostViewBase* platform_widget =
       platform_view_->CreateViewForWidget(render_widget_host);
 
-  RenderWidgetHostViewBase* view = new RenderWidgetHostViewGuest(
-      render_widget_host,
-      guest_,
-      platform_widget);
-
-  return view;
+  return new RenderWidgetHostViewGuest(render_widget_host,
+                                       guest_,
+                                       platform_widget);
 }
 
 RenderWidgetHostViewBase* WebContentsViewGuest::CreateViewForPopupWidget(