Bug 1197824 - Allow zooming in desktop mode. r=botond

This is a long-standing issue that has thus far never been exposed because
the values modified in this patch have not been used (desktop mode only exists
on Fennec, and Fennec does it's own computation for these values in browser.js).
However upcoming patches will change Fennec to use this, and so this issue needs
to be corrected.

--HG--
extra : commitid : 9BjFOc4PdLc

dom/base/nsDocument.cpp

@@ -7934,8 +7934,8 @@ nsDocument::GetViewportInfo(const ScreenIntSize& aDisplaySize)
     ScreenSize viewportSize(viewportWidth, viewportWidth * aspectRatio);
     return nsViewportInfo(RoundedToInt(viewportSize),
                           CSSToScreenScale(scaleToFit),
-                          /*allowZoom*/false,
-                          /*allowDoubleTapZoom*/ false);
+                          /*allowZoom*/ true,
+                          /*allowDoubleTapZoom*/ true);
   }
 
   if (!gfxPrefs::MetaViewportEnabled()) {