title: Viewport, target-densitydpi, pixelratio behaviour in chrome/mozilla on galaxy tab/nexus 7
body: <p>&lt;'meta name="viewport" content="width=device-width initial-scale=1.0, maximum-scale=1.0, target-densitydpi=..., user-scalable=0" />'<br>
  tested on different devices and browsers. Both tablets have 1280*800px physical resolution. The galaxy tab 10" the nexus 7 7". </p>
  
  <p>Chrome + device-dpi <br>
  galaxy : viewportwidth 1279px,   pixel ratio 1, screen.width 1280<br>
  nexus7 : vp            1279px,   pr 1.3312...,  sw 1280<br>
  <br>
  Chrome + high-dpi <br>
  galaxy : vp 1919px, pr 1,         sw 1280<br>
  nexus7 : vp 1441px,   pr 1.3312..., sw 1280<br>
  <br>
  Chrome + low-dpi <br>
  galaxy : vp  959px,  pr 1,         sw 1280<br>
  nexus7 : vp 720px,   pr 1.3312..., sw 1280<br>
  <br>
  <br>
  Now with Firefox (15/19) +  <br>
  galaxy : vp  1280px,  pr undefined, sw 1280<br>
  nexus7 : vp 853px,   pr 1, sw 1280<br></p>
  
  <p>The 853px are 1280 * 2/3. </p>
  
  <p>Now changing the width attribute to any discrete value like 1280
  and removing the scale boundaries both tablets get their viewports of 1280. 
  Leaving width blank or set to "auto" the Vieport results in<br>
  
  galaxy : vp  980px,  pr undefined, sw 1280<br>
  nexus7 : vp 980px,   pr 1, sw 1280<br></p>
  
  <p>Can anybody explain that to me? target-densitydpi is not supported by mozilla. 
  So it does have no effect. 
  And pixelratio is undefined in mozilla versions before 18 i think?
  1) Is the mozilla scaling by 2/3 on the nexus based on android or is it a "feature" of mozilla? 
  2) Where do the 980px come from? Its the same as setting "auto" to width. But how come that both devices get a viewport.width of 980? Some default from W3C?</p>