bar-tab and content view not fixed
My phone is Android 4.0+ and chrome is 34.0.1847.114 .
use default browser ,the bar-tab always show, not fixed to the bottom,
![default browser](https://cloud.githubusercontent.com/assets/3469132/2872028/419660be-d33c-11e3-9c25-6cb6c70bada9.jpg)

and in chrome, the bar-tab is show like default browser but transparent, and the content disappeared, scroll to the view outside.

![not input](https://cloud.githubusercontent.com/assets/3469132/2872030/5172a8e4-d33c-11e3-9c52-82980b79c638.jpg)

the input focused ..
![input](https://cloud.githubusercontent.com/assets/3469132/2872031/603a599e-d33c-11e3-9931-79ef33662411.jpg)

the html structure:

``` html
<body>

<!-- Make sure all your bars are the first things in your <body> -->
<header class="bar bar-nav">
    <h1 class="title">Ratchet</h1>
</header>

<nav class="bar bar-tab">
    <a class="tab-item active" href="#">
        <span class="icon icon-home"></span>
        <span class="tab-label">Home</span>
    </a>
    <a class="tab-item" href="#">
        <span class="icon icon-person"></span>
        <span class="tab-label">Profile</span>
    </a>
    <a class="tab-item" href="#">
        <span class="icon icon-star-filled"></span>
        <span class="tab-label">Favorites</span>
    </a>
    <a class="tab-item" href="#">
        <span class="icon icon-search"></span>
        <span class="tab-label">Search</span>
    </a>
    <a class="tab-item" href="#">
        <span class="icon icon-gear"></span>
        <span class="tab-label">Settings</span>
    </a>
</nav>



<!-- Wrap all non-bar HTML in the .content div (this is actually what scrolls) -->
<div class="content">
    <form>
        <input type="text" placeholder="username">
        <input type="password" placeholder="Password">
        <button class="btn btn-positive btn-block">Login</button>
    </form>
</div>

</body>
```
