Tests that turning on device emulation with a non-1 device pixel ratio sets the
    appropriate initial scale. Page scale is reflected by the innerWidth and
    innerHeight properties. Since the layout width is set to 980 (in the viewport
    meta tag), and the emulated viewport width is 490 px, the initial scale should
    be 490/980 = 0.5. i.e. innerWidth=980 innerHeight=640.
Emulating device: 490x320x3
Loading page with viewport=w=980
Device:
window.screenX = 0px
window.screenY = 0px
Viewport: = ?w=980
@media orientation = landscape
window.orientation = 0
@media resolution = 288dpi
@media device-pixel-ratio = 3
window.devicePixelRatio = 3
Widths:
@media device-width = 490px
screen.width = 490px
screen.availWidth = 490px
window.outerWidth = 490px
window.innerWidth = 980px
@media width = 980px
doc.docElem.clientWidth = 980px
doc.docElem.offsetWidth = 980px
doc.docElem.scrollWidth = 980px
doc.body.clientWidth = 980px
doc.body.offsetWidth = 980px
doc.body.scrollWidth = 980px
Heights:
@media device-height = 320px
screen.height = 320px
screen.availHeight = 320px
window.outerHeight = 320px
window.innerHeight = 640px
@media height = 640px
doc.docElem.clientHeight = 1000px
doc.docElem.offsetHeight = 1000px
doc.docElem.scrollHeight = 1000px
doc.body.clientHeight = 640px
doc.body.offsetHeight = 1000px
doc.body.scrollHeight = 1000px