Cleanup unused #includes and declarations in PlatformImpl

Cleanup unused #includes and declarations in PlatformImpl

These aren't needed anymore. Also, use more |override|.

R=eseidel@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/3714dbabb5e7a5a1a7446c7a7dd068dd7bb0b7ab

[eseidel, 2015-02-01 18:32:06]

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

[eseidel, 2015-02-01 18:32:06]

So the purpose of this is for portability.  So that you can easily wire it up to
[NSLocale defaultLocale] on mac, and whatever on windows.

Obviously we're android-only at this point, so we have waaaay too much
portability layer.  But I would also caution throwing it all out.

How will we set the default locale on a non-english system after this change?

[eseidel, 2015-02-01 18:32:52]

That can also be a later problem.  If you're going to do this, add a TODO that
we should wire this up to the host system's default locale.

[eseidel, 2015-02-01 18:33:46]

Does base have a locale system?

[abarth-chromium, 2015-02-01 19:10:42]

Ok.  Let's leave this.  I'll post a new CL with just the cleanup part of this
patch.

On 2015/02/01 at 18:33:46, eseidel wrote:
> Does base have a locale system?

I traced how this works in Chromium.  The locale comes in from BrowserMain.  We
get it from the pref store, which I think means it's based on which Chrome
installer you used (or maybe the installer makes a guess at install-time).

[abarth-chromium, 2015-02-01 19:11:37]

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/chr...

[abarth-chromium, 2015-02-01 19:14:55]

PTAL (just cleanup now)

[eseidel, 2015-02-01 20:49:43]

lgtm

Entertainingly platform/ used to be all non-virtual compile-time interfaces
before Chromium came on the scene.

[abarth-chromium, 2015-02-01 21:40:47]

Committed patchset #2 (id:20001) manually as
3714dbabb5e7a5a1a7446c7a7dd068dd7bb0b7ab (presubmit successful).