[NaCl SDK] Expose Google Drive to nacl_io.

native_client_sdk/src/examples/demo/nacl_io_demo/index.html

Index: native_client_sdk/src/examples/demo/nacl_io_demo/index.html
diff --git a/native_client_sdk/src/examples/demo/nacl_io_demo/index.html b/native_client_sdk/src/examples/demo/nacl_io_demo/index.html
index bf9d7ea30dc9de448f580398fa05025d1410adfd..aff6308ea0cec63a607b52069b4ea30dd5df05b5 100644
--- a/native_client_sdk/src/examples/demo/nacl_io_demo/index.html
+++ b/native_client_sdk/src/examples/demo/nacl_io_demo/index.html
@@ -25,7 +25,7 @@ found in the LICENSE file.
     directories, the mount determines how those operations should be performed.
   </p>
   <p>
-    This example has four mounts by default.
+    This example has five mounts by default.
     <ol>
       <li><i>/</i> the root of the filesystem. This is a memory mount, and
           is non-persistent.</li>
@@ -35,6 +35,11 @@ found in the LICENSE file.
           /http/index.html.</li>
       <li><i>/dev</i> a mount containing some utility files. /dev/null,
           /dev/zero, etc.</li>
+      <li><i>/googledrive</i> a Google Drive mount. Before using, client ID 
+          and client secret, created from Google Developers Console, have to 
+          be filled in in example.js. When they have already been filled, 
+          use makefile on nacl_io_demo, and click on the sign-in button to 
+          expose Google Drive to nacl_io.</li>
     </ol>
   </p>
   <p>
@@ -43,6 +48,12 @@ found in the LICENSE file.
     API, an app must be a packaged app with the appropriate socket permissions
     specified in the manifest file.
   <hr>
+  <p><b>Google account sign-in for Google Drive mount:</b></p>
+  <button id="buttonsignin" onclick="buttonOnClick()">Sign in</button>
+  <script>
+    executeAfterGettingCode();
+  </script>
+  <hr>
   <p><b>File Operations:</b></p>
   <div>
     <span>