Added dart:js samples landing pages.

src/site/samples/gauge/index.markdown

Index: src/site/samples/gauge/index.markdown
diff --git a/src/site/samples/gauge/index.markdown b/src/site/samples/gauge/index.markdown
new file mode 100644
index 0000000000000000000000000000000000000000..8bb48be03b0f29a547523dcb2482cf3873eaf8e0
--- /dev/null
+++ b/src/site/samples/gauge/index.markdown
@@ -0,0 +1,30 @@
+---
+layout: default
+title: Google Charts API and dart:js
+live_example_url: example/gauge.html
+
+header:
+  css: ["/samples/samples.css"]
+---
+
+## {{ page.title }}
+
+This code derives from the Google Charts JavaScript API
+[Gauge Visualization](
+https://developers.google.com/chart/interactive/docs/gallery/gauge#Example)
+examples. The example uses the `dart:js` library for Dart and JavaScript
+interoperability.
+
+Read the [dart:js API
+docs](http://api.dartlang.org/docs/releases/latest/dart_js.html).
+
+Read the
+[source](https://code.google.com/p/dart/source/browse/#svn%2Fbranches%2Fbleeding_edge%2Fdart%2Fsamples%2Fgauge).
+
+<iframe class="running-app-frame"
+        style="height:600px;width:100%;"
+        src="{{page.live_example_url}}"
+        align="middle">
+</iframe>
+
+See all [samples](/samples/)