Use FrameTreeNode ID as frameId in extension APIs

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

Index: chrome/test/data/extensions/api_test/webnavigation/crossProcessIframe/frame.js
diff --git a/chrome/test/data/extensions/api_test/webnavigation/crossProcessIframe/frame.js b/chrome/test/data/extensions/api_test/webnavigation/crossProcessIframe/frame.js
new file mode 100644
index 0000000000000000000000000000000000000000..72f0167e7da995c31f3817f64c6d339a72fd100d
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/webnavigation/crossProcessIframe/frame.js
@@ -0,0 +1,17 @@
+// 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") {
+      // 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);
+};