Replace ResultProvider with 'aboutToComputeResult'.

Replace ResultProvider with 'aboutToComputeResult'.

This way we would be able to redirect to the SDK context, or get some
results from packages. Setting ResultProvider into AnalysisDriver does
not allow us to do this.

My quick and dirty experiment with using SDK summaries is broken now,
but I'm going to start updating actual SdkAnalysisContext using
summaries, if the bundle exists in the SDK.

R=brianwilkerson@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/a2d615e52a505db2206c7971aa2d9e1dc8c7e87f

[Brian Wilkerson, 2016-01-04 18:03:02]

LGTM

[scheglov, 2016-01-04 18:19:20]

Description was changed from

==========
Replace ResultProvider with 'aboutToComputeResult'.

This way we would be able to redirect to the SDK context, or get some
results from packages. Setting ResultProvider into AnalysisDriver does
not allow us to do this.

My quick and dirty experiment with using SDK summaries is broken now,
but I'm going to start updating actual SdkAnalysisContext using
summaries, if the bundle exists in the SDK.

R=brianwilkerson@google.com
BUG=
==========

to

==========
Replace ResultProvider with 'aboutToComputeResult'.

This way we would be able to redirect to the SDK context, or get some
results from packages. Setting ResultProvider into AnalysisDriver does
not allow us to do this.

My quick and dirty experiment with using SDK summaries is broken now,
but I'm going to start updating actual SdkAnalysisContext using
summaries, if the bundle exists in the SDK.

R=brianwilkerson@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/a2d615e52a505db2206c7971aa2d9e1dc8c7e87f
==========

[scheglov, 2016-01-04 18:19:21]

Committed patchset #1 (id:1) manually as
a2d615e52a505db2206c7971aa2d9e1dc8c7e87f (presubmit successful).