Add the ability to deprecate Flatbuffer fields.

Add the ability to deprecate Flatbuffer fields.

If an IDL field is marked as `@deprecated`, no setter will be
generated for it, and the getter generated for it will throw an
UnimplementedError.  This is similar to the behavior of standard
Flatbuffer tools (which generate neither setters nor getters for
deprecated fields) except that we have to generate a getter in order
to avoid warnings.

Once we have begun using summaries in the wild, we will need to make
use of this feature in order to avoid changing Id numbers and breaking
backwards compatibility.

R=scheglov@google.com

Committed: https://github.com/dart-lang/sdk/commit/9a983bcbda79115fbffc4621d44f6b5f06e28948

[Paul Berry, 2016-03-01 19:23:20]

paulberry@google.com changed reviewers:
+ scheglov@google.com

[scheglov, 2016-03-01 20:24:45]

LGTM

[Paul Berry, 2016-03-01 21:25:08]

Description was changed from

==========
Add the ability to deprecate Flatbuffer fields.

If an IDL field is marked as `@deprecated`, no setter will be
generated for it, and the getter generated for it will throw an
UnimplementedError.  This is similar to the behavior of standard
Flatbuffer tools (which generate neither setters nor getters for
deprecated fields) except that we have to generate a getter in order
to avoid warnings.

Once we have begun using summaries in the wild, we will need to make
use of this feature in order to avoid changing Id numbers and breaking
backwards compatibility.
==========

to

==========
Add the ability to deprecate Flatbuffer fields.

If an IDL field is marked as `@deprecated`, no setter will be
generated for it, and the getter generated for it will throw an
UnimplementedError.  This is similar to the behavior of standard
Flatbuffer tools (which generate neither setters nor getters for
deprecated fields) except that we have to generate a getter in order
to avoid warnings.

Once we have begun using summaries in the wild, we will need to make
use of this feature in order to avoid changing Id numbers and breaking
backwards compatibility.

R=scheglov@google.com

Committed:
https://github.com/dart-lang/sdk/commit/9a983bcbda79115fbffc4621d44f6b5f06e28948
==========

[Paul Berry, 2016-03-01 21:25:09]

Committed patchset #1 (id:1) manually as
9a983bcbda79115fbffc4621d44f6b5f06e28948 (presubmit successful).