Viewport/Client Width in a Lightning App

I was able to reproduce the clientWidth issue using chrome simulator as described in the question.

So I tried adding the meta tag to the Lightning app directly and logged the clientWidth and it is properly returning the width based on the viewport when tested with the chrome simulator.

myApp.app:

<aura:application extends="force:slds">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"/>
    <div style="background: grey">
        foo
    </div>
    <button type="button" class="slds-button slds-button--brand" onclick="{!c.logwidth}">logwidth</button>

</aura:application>

myAppController.js

({
    logwidth : function(cmp, event, helper) {
        console.log(document.documentElement.clientWidth )
    }
})