Sandbox windows not provided to chrome.app.window.create.

Documented in developer console, avoiding raising an exception, and
on developer documentation page sample.

BUG=154662

Review URL: https://codereview.chromium.org/1107163002

Cr-Commit-Position: refs/heads/master@{#327421}

chrome/common/extensions/docs/templates/articles/app_external.html

@@ -178,14 +178,11 @@ one for the main app window that isn't sandboxed,
 and one for the sandboxed page:
 </p>
 
-<p class="warning">
+<p class="note">
 NOTE:
-<a href="https://code.google.com/p/chromium/issues/detail?id=154662">issue 154662</a>
-is a bug when using sandbox pages to create windows.
-The effect is that an error "Uncaught TypeError: Cannot call method
-'initializeAppWindow' of undefined" is output to the developer console
-and that the app.window.create call does not call the callback function
-with a window object. However, the sandbox page is created as a new window.
+A sandboxed window will not have access to the chrome.app APIs. If a
+callback is provided to app.window.create it will be run, but will not have
+the sandboxed window provided to it.
 </p>
 
 <pre data-filename="background.js">

extensions/renderer/resources/app_window_custom_bindings.js

@@ -140,10 +140,21 @@ appWindow.registerCustomHook(function(bindingsAPI) {
     }
 
     // Initialize appWindowData in the newly created JS context
-    view.chrome.app.window.initializeAppWindow(windowParams);
+    if (view.chrome.app) {
+      view.chrome.app.window.initializeAppWindow(windowParams);
+    } else {
+      var sandbox_window_message = 'Creating sandboxed window, it doesn\'t ' +
+          'have access to the chrome.app API.';
+      if (callback) {
+        sandbox_window_message = sandbox_window_message +
+            ' The chrome.app.window.create callback will be called, but ' +
+            'there will be no object provided for the sandboxed window.';
+      }
+      console.warn(sandbox_window_message);
+    }
 
     if (callback) {
-      if (!view) {
+      if (!view || !view.chrome.app /* sandboxed window */) {
         callback(undefined);
         return;
       }