The components are not available to build the Web Page

[debroy5]

I have tried using the bellow URL to create a chart
https://polymer-designer.appspot.com/
I made the script changes in Code View.
The moment I am toggling the Code view to designer view, everything I modified in the Script tag is getting erased.

I tried getting the code from Github. After performing all the dependencies when I am executing (http://localhost:8080), i dont see all the controls (similar to https://polymer-designer.appspot.com/). I am getting the code from the Master branch