<webview>, <appview> and <extensionoptions> can run in a detached state.

extensions/browser/guest_view/web_view/web_view_guest.cc

Index: extensions/browser/guest_view/web_view/web_view_guest.cc
diff --git a/extensions/browser/guest_view/web_view/web_view_guest.cc b/extensions/browser/guest_view/web_view/web_view_guest.cc
index 1cce121bdb98beb7413030c964a8d7f9a20400a8..bbd4e14857fcccab6c6db8c21636a056170164ba 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.cc
+++ b/extensions/browser/guest_view/web_view/web_view_guest.cc
@@ -220,12 +220,8 @@ int WebViewGuest::GetViewInstanceId(WebContents* contents) {
   return guest->view_instance_id();
 }
 
-const char* WebViewGuest::GetAPINamespace() const {
-  return webview::kAPINamespace;
-}
-
-int WebViewGuest::GetTaskPrefix() const {
-  return IDS_EXTENSION_TASK_MANAGER_WEBVIEW_TAG_PREFIX;
+bool WebViewGuest::CanRunInDetachedState() const {
+  return true;
 }
 
 void WebViewGuest::CreateWebContents(
@@ -308,8 +304,7 @@ void WebViewGuest::DidInitialize(const base::DictionaryValue& create_params) {
   // requests.
   PushWebViewStateToIOThread();
 
-  // TODO(fsamuel): Once <webview> can run in a detached state, call
-  // ApplyAttributes here.
+  ApplyAttributes(create_params);
 }
 
 void WebViewGuest::AttachWebViewHelpers(WebContents* contents) {
@@ -343,6 +338,14 @@ void WebViewGuest::EmbedderWillBeDestroyed() {
           view_instance_id()));
 }
 
+const char* WebViewGuest::GetAPINamespace() const {
+  return webview::kAPINamespace;
+}
+
+int WebViewGuest::GetTaskPrefix() const {
+  return IDS_EXTENSION_TASK_MANAGER_WEBVIEW_TAG_PREFIX;
+}
+
 void WebViewGuest::GuestDestroyed() {
   // Clean up custom context menu items for this guest.
   if (web_view_guest_delegate_)
@@ -486,10 +489,6 @@ void WebViewGuest::OnFrameNameChanged(bool is_top_level,
   ReportFrameNameChange(name);
 }
 
-bool WebViewGuest::CanRunInDetachedState() const {
-  return false;
-}
-
 void WebViewGuest::CreateNewGuestWebViewWindow(
     const content::OpenURLParams& params) {
   GuestViewManager* guest_manager =