improve analysis server notifications

improve analysis server notifications
* add context id to error notifications
* add analysis.complete notification

BUG=
R=paulberry@google.com

Committed: https://code.google.com/p/dart/source/detail?r=36363

[Brian Wilkerson, 2014-05-20 13:49:23]

What are the use cases for these changes?

[Paul Berry, 2014-05-20 15:34:58]

lgtm assuming comment is addressed

https://codereview.chromium.org/299513003/diff/20001/pkg/analysis_server/lib/...
File pkg/analysis_server/lib/src/analysis_server.dart (right):

https://codereview.chromium.org/299513003/diff/20001/pkg/analysis_server/lib/...
pkg/analysis_server/lib/src/analysis_server.dart:188: var notification = new
Notification(ANALYSIS_COMPLETE);
I'm concerned that this is going to lead to bugs, because it provides no way for
the client to reliably know when analysis has started, so it's going to have to
guess.  If it fails to guess that analysis has started when it actually has, the
user will see no indication that analysis is going on.  If it falsely guesses
that analysis has started when it actually hasn't, it will appear to the user
that analysis is stuck in an infinite loop.

Also, based on features present in other refactoring editors, I suspect we're
eventually going to want to also communicate information like:

- What file is currently being analyzed
- Analysis progress (e.g. we have analyzed N files out of M)
- Estimated time until analysis completes

I would rather see an "analysis status" notification, containing this sort of
information in a map.  Initially we can just populate the map with a single
boolean to indicate whether analysis is in progress or not, and later we can add
other fields.

[danrubel, 2014-05-20 16:37:02]

On 2014/05/20 15:34:58, Paul Berry wrote:
> lgtm assuming comment is addressed
> 
>
https://codereview.chromium.org/299513003/diff/20001/pkg/analysis_server/lib/...
> File pkg/analysis_server/lib/src/analysis_server.dart (right):
> 
>
https://codereview.chromium.org/299513003/diff/20001/pkg/analysis_server/lib/...
> pkg/analysis_server/lib/src/analysis_server.dart:188: var notification = new
> Notification(ANALYSIS_COMPLETE);
> I'm concerned that this is going to lead to bugs, because it provides no way
for
> the client to reliably know when analysis has started, so it's going to have
to
> guess.  If it fails to guess that analysis has started when it actually has,
the
> user will see no indication that analysis is going on.  If it falsely guesses
> that analysis has started when it actually hasn't, it will appear to the user
> that analysis is stuck in an infinite loop.
> 
> Also, based on features present in other refactoring editors, I suspect we're
> eventually going to want to also communicate information like:
> 
> - What file is currently being analyzed
> - Analysis progress (e.g. we have analyzed N files out of M)
> - Estimated time until analysis completes
> 
> I would rather see an "analysis status" notification, containing this sort of
> information in a map.  Initially we can just populate the map with a single
> boolean to indicate whether analysis is in progress or not, and later we can
add
> other fields.

Per discussion I'm dropping the 'analysis.complete' from this CL in favor of an
'analysis.update' notification in a separate CL.

[danrubel, 2014-05-20 16:42:58]

Committed patchset #3 manually as r36363 (presubmit successful).