Use FrameTreeNode ID as frameId in extension APIs

chrome/test/data/extensions/api_test/webnavigation/crossProcessIframe/frame.js

+// Copyright 2015 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.
+
+onload = function() {
+  setTimeout(function() {
+    if (location.hostname === "a.com") {

[Devlin, 2015/11/13 21:16:27]

nitty nit: prefer single-quotes in js (except to avoid escapes)

[robwu, 2015/12/07 23:44:22]

Done.

+      // Do nothing. The parent frame should navigate us.
+    } else if (location.hostname === "b.com") {
+      // Trigger a navigation to a site in another process.
+      location.hostname = "c.com";
+    } else {
+      console.assert(location.hostname === "c.com");
+      // Done.
+    }
+  }, 0);
+};