Revert 274879 "Revert 274326 "Lobotomize the GPU memory manager""

Revert 274879 "Revert 274326 "Lobotomize the GPU memory manager""

> Revert 274326 "Lobotomize the GPU memory manager"
> BUG=380666
>
> > Lobotomize the GPU memory manager
> >
> > On desktop, always set the memory limit to 256MB, and ask that the renderer
> > only use that memory to draw content that is near the viewport. The effective
> > limit prior to this patch was 384MB, but would quickly get cut down as multiple
> > windows are opened, but would not fall too much lower than 256MB (e.g, 128
> > on Mac).
> >
> > On mobile, use all available memory for the current, only, renderer.
> >
> > Do not take into account unmanaged (e.g, WebGL) memory usage.
> >
> > BUG=377065
> >
> > Review URL: https://codereview.chromium.org/308743005
>
> TBR=ccameron@chromium.org
>
> Review URL: https://codereview.chromium.org/313163002

TBR=ccameron@chromium.org

Review URL: https://codereview.chromium.org/338593003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@277056 0039d316-1c4b-4281-b951-d872f2087c98