Remove x,y,width,height from HTMLImageElement.

Remove x,y,width,height from HTMLImageElement.

This conflicts with adding them to HTMLElement for custom layout.
I grepped the codebase and couldn't find any uses of these. The
big thing we lose here is a way to set width/height on an image
that automatically maintains aspect ratio, but that's something
we should move into a custom layout method anyways.

R=eseidel@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/b508ec15783c87289a7f1e27bc487e46cef64494

[eseidel, 2015-04-02 22:13:06]

eseidel@chromium.org changed reviewers:
+ eseidel@chromium.org

[eseidel, 2015-04-02 22:13:07]

Do you want to remove the c++ too? lgtm

[ojan, 2015-04-02 22:13:51]

On 2015/04/02 at 22:13:07, eseidel wrote:
> Do you want to remove the c++ too? lgtm

Hah. Good point. I'll actually do that in a followup set of patches since
there's a good chunk of stuff to delete and this blocks my other custom layout
patches.

[ojan, 2015-04-02 22:15:54]

Committed patchset #1 (id:1) manually as
b508ec15783c87289a7f1e27bc487e46cef64494 (presubmit successful).