Restructure public side of view_manager service.

Restructure public side of view_manager service.

This CL goes from this:
//mojo/services/public/cpp/view_manager
//mojo/services/public/interfaces/view_manager

to this:
//mojo/services/view_manager/public/cpp
//mojo/services/view_manager/public/interfaces

This CL also makes the Mojo-side changes required to roll this change into
Chromium (for both view_manager and window_manager, which was converted in an
earlier CL but for which these updates were not made):
- Updates rev_sdk.py to pull over the new directory
- Updates //mojo/services/public/mojo_services_public.gyp

TBR=beng

Committed: https://chromium.googlesource.com/external/mojo/+/c4edbc7a49a0f8326c2cd94084f099cb8c8faae2

[blundell, 2014-12-10 13:11:21]

blundell@chromium.org changed reviewers:
+ beng@chromium.org

[blundell, 2014-12-10 13:16:35]

Committed patchset #4 (id:60001) manually as
c4edbc7a49a0f8326c2cd94084f099cb8c8faae2 (presubmit successful).

[Ben Goodger (Google), 2014-12-10 21:33:46]

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

[Ben Goodger (Google), 2014-12-10 21:33:47]

lgtm