Make it so that allow_js_access: false can be used with background pages created by window.open.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 76de2316615e11e70554fe75e7c8a6a46b0b08d2..9182a463bbd788ba00943e0379d4f7b126050e6e 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -1259,7 +1259,8 @@ void ChromeContentBrowserClient::CancelDesktopNotification(
 #endif
 }
 
-bool ChromeContentBrowserClient::CanCreateWindow(
+content::ContentBrowserClient::CanCreateWindowResult
+ChromeContentBrowserClient::CanCreateWindow(
     const GURL& opener_url,
     const GURL& source_origin,
     WindowContainerType container_type,
@@ -1272,23 +1273,25 @@ bool ChromeContentBrowserClient::CanCreateWindow(
     ProfileIOData* io_data = ProfileIOData::FromResourceContext(context);
     ExtensionInfoMap* map = io_data->GetExtensionInfoMap();
 
-    // If the opener is not allowed to script its background window, then return
-    // false so that the window.open call returns null.  In this case, only
-    // the manifest is permitted to create a background window.
+    if (!map->SecurityOriginHasAPIPermission(
+        source_origin,
+        render_process_id,
+        ExtensionAPIPermission::kBackground)) {
+      return CANNOT_CREATE_WINDOW;
+    }
+
     // Note: this use of GetExtensionOrAppByURL is safe but imperfect.  It may
     // return a recently installed Extension even if this CanCreateWindow call
     // was made by an old copy of the page in a normal web process.  That's ok,
-    // because the permission check below will still fail.  We must use the
-    // full URL to find hosted apps, though, and not just the origin.
+    // because the permission check above would have caused an early return
+    // already. We must use the full URL to find hosted apps, though, and not
+    // just the origin.
     const Extension* extension = map->extensions().GetExtensionOrAppByURL(
         ExtensionURLInfo(opener_url));
     if (extension && !extension->allow_background_js_access())
-      return false;
-
-    return map->SecurityOriginHasAPIPermission(
-        source_origin, render_process_id, ExtensionAPIPermission::kBackground);
+      return CAN_CREATE_WINDOW_NO_JS_ACCESS;
   }
-  return true;
+  return CAN_CREATE_WINDOW;
 }
 
 std::string ChromeContentBrowserClient::GetWorkerProcessTitle(