I would to make the iFrame to appear on fullscreen with a button click using JavaScript.
<iframe id="iframe_view" class="embed-responsive-item container well well-small span6" style="height: 720px; width: 1280px; background-color: #2e2e2e;" src="https://www.google.com/" frameborder="0" scrolling="no" allowfullscreen>
You will have to do two things: make the window fullscreen, and then the
<iframe>
to fill up the whole size.You can make it go fullscreen with JS such as in this SO answer.
Then, to make it full size, just add a few styles, like below. What this JS script does is add a class with those styles to the
<iframe>
.JS
CSS
See this partially working* example on JSFiddle.
*partially working because JSFiddle doesn't allow the fullscreen method because it deems it unsafe. But it should work for you.