Move chrome.appWindow to chrome.app.window.

chrome/common/extensions/docs/static/app_external.html

 <div id="pageData-name" class="pageData">Embed Content</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 The <a href="app_architecture.html#security">packaged apps security model</a> disallows
 external content in iframes and
 the use of inline scripting and <code>eval()</code>.
 You can override these restrictions,
 but your external content must be isolated from the app.
 </p>
@@ skipping 163 matching lines @@
 <p>
 Just like any other app pages,
 you can create a window that the sandboxed page opens in.
 Here's a sample that creates two windows,
 one for the main app window that isn't sandboxed,
 and one for the sandboxed page:
 </p>
 
 <pre>
 chrome.experimental.app.onLaunched.addListener(function() {
-  chrome.appWindow.create('window.html', {
+  chrome.app.window.create('window.html', {
     'width': 400,
     'height': 400,
     'left': 0,
     'top': 0
   });
 
-  chrome.appWindow.create('sandboxed.html', {
+  chrome.app.window.create('sandboxed.html', {
     'width': 400,
     'height': 400,
     'left': 400,
     'top': 0
   });
 });
 </pre>
 
 <h3>Embedding a sandboxed page in an app page</h3>
 
@@ skipping 29 matching lines @@
 between your app and sandboxed content.
 Here's a sample background script
 that posts a message to the sandboxed page it
 opens:
 </p>
 
 <pre>
 var myWin = null;
 
 chrome.experimental.app.onLaunched.addListener(function() {
-  chrome.appWindow.create('sandboxed.html', {
+  chrome.app.window.create('sandboxed.html', {
     'width': 400,
     'height': 400
   }, function(win) {
        myWin = win;
        myWin.postMessage('Just wanted to say hey.', '*');
      });
 });
 </pre>
 
 <p>
@@ skipping 22 matching lines @@
 <pre>
 var messageHandler = function(e) {
   console.log('Background script says hello.', e.data);
 };
 
 window.addEventListener('message', messageHandler);
 </pre>
 
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