Fix CurrentMapForDeprecated() to return MaybeHandle instead of a null handle.

Fix CurrentMapForDeprecated() to return MaybeHandle instead of a null handle.

Also fix TryMigrateInstance() to return bool instead of the parameter or
a null handle.

R=yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=20996

[Benedikt Meurer, 2014-04-25 11:06:05]

PTAL

[Yang, 2014-04-25 11:48:06]

LGTM with comment.

https://codereview.chromium.org/251683003/diff/1/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/251683003/diff/1/src/objects.h#newcode6461
src/objects.h:6461: static MaybeHandle<Map> CurrentMapForDeprecated(Handle<Map>
map);
We generally mark functions that return MaybeHandle with MUST_USE_RESULT to
enforce result checking. Maybe we want to do it here as well?

[Benedikt Meurer, 2014-04-26 10:12:42]

https://codereview.chromium.org/251683003/diff/1/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/251683003/diff/1/src/objects.h#newcode6461
src/objects.h:6461: static MaybeHandle<Map> CurrentMapForDeprecated(Handle<Map>
map);
On 2014/04/25 11:48:06, Yang wrote:
> We generally mark functions that return MaybeHandle with MUST_USE_RESULT to
> enforce result checking. Maybe we want to do it here as well?

Done.

[Benedikt Meurer, 2014-04-28 05:47:51]

Committed patchset #2 manually as r20996 (presubmit successful).