Adding two codelabs for cds2014.

native_client_sdk/src/doc/nacldev/clipboard_app.inc

+Clipboard
+=========
+
+Many of the steps in this tutorial will be easier to copy and paste
+into the Dev Environment.
+To copy and paste in the Dev Environment App,
+you will need to use the keyboard.
+
+On your platform use:
+
+  * |copy_key| to Copy
+  * |paste_key| to Paste
+
+.. |copy_key| raw:: html
+
+  <span id="copy_key">Loading...</span>
+  <script>
+  var tag = document.getElementById('copy_key');
+  if (navigator.appVersion.indexOf('Mac') >= 0) {
+    tag.innerHTML = '&#8984;-C';
+  } else {
+    tag.innerHTML = 'Ctrl-Shift-C';
+  }
+  </script>
+
+.. |paste_key| raw:: html
+
+  <span id="paste_key">Loading...</span>
+  <script>
+  var tag = document.getElementById('paste_key');
+  if (navigator.appVersion.indexOf('Mac') >= 0) {
+    tag.innerHTML = '&#8984;-V';
+  } else {
+    tag.innerHTML = 'Ctrl-Shift-V';
+  }
+  </script>