Revert of Center images when loading image urls in the main frame. (https://codereview.chromium.org/247293005/)

Reason for revert:
Caused regressions in the display/zooming of very large images.

Original issue's description:
> Center images when loading image urls in the main frame.
> 
> Do the same as Firefox and Presto when displaying raw image urls in the
> main frame: center them in the view.
> 
> If this works out OK we should apply it to images loaded in iframes too.
> 
> BUG=27987
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=172169

TBR=eseidel@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=27987

Review URL: https://codereview.chromium.org/256173002

git-svn-id: svn://svn.chromium.org/blink/trunk@172783 bbb929c8-8fbe-4397-9dbb-9b2b20218538