Revert 231982 "Docserver: Display enum value descriptions in API..."

"JsonSchemaTest.TestEnum" started failing on Windows bot after this change.

> Docserver: Display enum value descriptions in API docs.
> 
> This modifies the json schema to allow both primitive types and
> dictionaries with properties "name" and optional "description" for enum
> values.
> 
> BUG=310454
> 
> Review URL: https://codereview.chromium.org/39113003

TBR=sammc@chromium.org

Review URL: https://codereview.chromium.org/47403003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232016 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232016