Added geolocation (new); surfaced appcache and webaudio samples

src/site/samples/webaudio/index.markdown

 ---
 layout: default
 title: Getting Started with the Web Audio API
 live_example_url: example/index.html
 
 header:
   css: ["/samples/samples.css"]
 ---
 
 ## {{ page.title }}
 
 A port of an example used in the
 [Getting Started with Web Audio API](http://www.html5rocks.com/en/tutorials/webaudio/intro/)
 article by Boris Smus, originally published on HTML5Rocks.
 
 You can use the Web Audio API for processing and synthesizing audio in web
 applications. The API lets you use functionality found in modern game audio
 engines and mixing, processing, and filtering tasks found in modern desktop
 audio production applications.
 
 You can open the example in Dart Editor and run it by clicking `index.html`.
 Read the
 [source](https://github.com/dart-lang/dart-samples/tree/master/web/html5/webaudio/intro).
 
 <iframe class="running-app-frame"
-        style="height:500px;width:100%;"
+        style="height:200px;width:100%;"
         src="{{page.live_example_url}}">
 </iframe>
 
 See all [samples](/samples/).