mac: Make Mach port scopers better ScopedGenerics

mac: Make Mach port scopers better ScopedGenerics

Previously, Pass() did not work correctly for ScopedMachReceiveRight,
ScopedMachSendRight, or ScopedMachPortSet. These were defined as
subclasses of ScopedGeneric<> with appropriate traits types. They did
not have the full range of constructors made available by
ScopedGeneric<>, and their Pass() methods referred to their
ScopedGeneric<> superclass rather than their proper class types.

This changes these scopers to work as ScopedGeneric<> intends, with a
"using" or "typedef" declaration, so that names such as
ScopedMachReceiveRight actually refer to the same type as the underlying
ScopedGeneric<>. This allows Pass() and all other ScopedGeneric<>
functionality to work as intended.

Unfortunately, ScopedGeneric<> doesn't provide a type conversion
operator to the underlying wrapped type, so many use sites need to be
transformed to use the get() accessor. Many existing use sites already
used this accessor.

Committed: https://crrev.com/da902e18a4d31bc1d1534f85ab6cf30b4c4bcdfc
Cr-Commit-Position: refs/heads/master@{#355112}

[Mark Mentovai, 2015-10-16 06:50:52]

mark@chromium.org changed reviewers:
+ avi@chromium.org, tsepez@chromium.org

[Mark Mentovai, 2015-10-16 06:50:52]

avi for content and overall review
tsepez for ipc

[Avi (use Gerrit), 2015-10-16 16:27:39]

lgtm

[Tom Sepez, 2015-10-16 16:29:59]

lgtm

[Mark Mentovai, 2015-10-20 17:42:45]

The CQ bit was checked by mark@chromium.org

[commit-bot: I haz the power, 2015-10-20 17:43:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1411523006/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1411523006/20001

[commit-bot: I haz the power, 2015-10-20 18:36:20]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-20 18:37:19]

Patchset 2 (id:??) landed as
https://crrev.com/da902e18a4d31bc1d1534f85ab6cf30b4c4bcdfc
Cr-Commit-Position: refs/heads/master@{#355112}