Move NSScrollerImpDetails to platform/mac/

Move NSScrollerImpDetails to platform/mac/

BUG=297477

[eseidel, 2013-11-11 18:34:59]

I thought Avi had recently inverted this logic so that the browser told us about
scroller changes instead of Blink watching for them?

[Avi (use Gerrit), 2013-11-11 18:59:50]

On 2013/11/11 18:34:59, eseidel wrote:
> I thought Avi had recently inverted this logic so that the browser told us
about
> scroller changes instead of Blink watching for them?

Some... not all.

I moved two notification handlers. There's a ton of work left in this area.

[pilgrim_google, 2013-11-12 14:51:38]

This file compiled when it was in core/platform/ but fails now in platform/ ,
which leads me to believe it's a gyp problem (failing to list some critical
Mac-specific framework or something). Nothing jumps out at me, though. Help?

Possibly the same problem as I'm having in
https://codereview.chromium.org/66023005/

[pilgrim_google, 2013-12-09 14:51:45]

Bump.

[abarth-chromium, 2013-12-09 17:36:01]

No logs here either...

[commit-bot: I haz the power, 2013-12-09 17:36:07]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[eseidel, 2013-12-09 18:19:38]

I suspect all of this stuff should be in rendering/mac along with RenderTheme
instead of platform.

But OK.

[eseidel, 2013-12-09 18:19:59]

lgtm