Allow an analysis server response to have both "error" and "result" fields.

Allow an analysis server response to have both "error" and "result" fields.

Usually this won't happen, but there are rare cases where it might
(e.g. an unexpected exception occurs while analyzing a file in
response to analysis.getErrors, and some error information has already
been successfully computed).

So it seems best to allow it in the integration tests.

R=jwren@google.com

Committed: https://code.google.com/p/dart/source/detail?r=38516

[jwren, 2014-07-23 17:21:21]

On 2014/07/23 16:58:26, Paul Berry wrote:

LGTM

[Paul Berry, 2014-07-23 18:10:14]

Committed patchset #1 manually as r38516 (presubmit successful).