Go bindings: Change generated enum value constants to be typed as the enum type.

Go bindings: Change generated enum value constants to be typed as the enum type.

This change does not address the debate in https://github.com/domokit/mojo/issues/765 regarding the naming of the enum value constants.
It only addresses the problem described in the bug description, namely that the enum constants do not have the right type.

- The primary change is in enum.tmpl
- I added a new test, enums_test.go. In so doing I beefed up test_enums.mojom. This required re-generating the Dart file for this mojom.
- Adding the test revealed an unrelated bug which I fixed in mojom_go_generatory.py

BUG=#765
R=vardhan@google.com

Committed: https://chromium.googlesource.com/external/mojo/+/2f2d1bece6eb2dae607edadbc7355cec65e892fb

[rudominer, 2016-05-03 01:14:34]

Patchset #2 (id:20001) has been deleted

[rudominer, 2016-05-03 01:14:46]

Patchset #2 (id:40001) has been deleted

[rudominer, 2016-05-03 01:14:58]

Patchset #2 (id:60001) has been deleted

[rudominer, 2016-05-03 01:15:08]

Patchset #2 (id:80001) has been deleted

[rudominer, 2016-05-03 01:20:08]

Description was changed from

==========
Go bindings: Change generated enum value constants to be typed as the enum type.

BUG=#765
==========

to

==========
Go bindings: Change generated enum value constants to be typed as the enum type.

This change does not address the debate in
https://github.com/domokit/mojo/issues/765 regarding the naming of the enum
value constants.
It only addresses the problem described in the bug description, namely that the
enum constants do not have the right type.

- The primary change is in enum.tmpl
- I added a new test, enums_test.go. In so doing I beefed up test_enums.mojom.
This required re-generating the Dart file for this mojom.
- Adding the test revealed an unrelated bug which I fixed in
mojom_go_generatory.py

BUG=#765
==========

[rudominer, 2016-05-03 01:21:38]

Patchset #1 (id:1) has been deleted

[rudominer, 2016-05-03 01:30:55]

rudominer@chromium.org changed reviewers:
+ vardhan@google.com

[rudominer, 2016-05-03 01:30:56]

Hi Vardhan, ptal.

[vardhan, 2016-05-03 17:04:26]

lgtm

[rudominer, 2016-05-03 17:24:47]

Description was changed from

==========
Go bindings: Change generated enum value constants to be typed as the enum type.

This change does not address the debate in
https://github.com/domokit/mojo/issues/765 regarding the naming of the enum
value constants.
It only addresses the problem described in the bug description, namely that the
enum constants do not have the right type.

- The primary change is in enum.tmpl
- I added a new test, enums_test.go. In so doing I beefed up test_enums.mojom.
This required re-generating the Dart file for this mojom.
- Adding the test revealed an unrelated bug which I fixed in
mojom_go_generatory.py

BUG=#765
==========

to

==========
Go bindings: Change generated enum value constants to be typed as the enum type.

This change does not address the debate in
https://github.com/domokit/mojo/issues/765 regarding the naming of the enum
value constants.
It only addresses the problem described in the bug description, namely that the
enum constants do not have the right type.

- The primary change is in enum.tmpl
- I added a new test, enums_test.go. In so doing I beefed up test_enums.mojom.
This required re-generating the Dart file for this mojom.
- Adding the test revealed an unrelated bug which I fixed in
mojom_go_generatory.py

BUG=#765
R=vardhan@google.com

Committed:
https://chromium.googlesource.com/external/mojo/+/2f2d1bece6eb2dae607edadbc73...
==========

[rudominer, 2016-05-03 17:24:49]

Committed patchset #1 (id:100001) manually as
2f2d1bece6eb2dae607edadbc7355cec65e892fb (presubmit successful).