Add FileSystemState.knownFilesSetChanges stream.

Add FileSystemState.knownFilesSetChanges stream.

R=brianwilkerson@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/7faf4bac9373f8128d29df9f58450825cebc03d4

[Brian Wilkerson, 2017-04-19 20:09:52]

lgtm

https://codereview.chromium.org/2826243002/diff/1/pkg/analyzer/lib/src/dart/a...
File pkg/analyzer/lib/src/dart/analysis/file_state.dart (right):

https://codereview.chromium.org/2826243002/diff/1/pkg/analyzer/lib/src/dart/a...
pkg/analyzer/lib/src/dart/analysis/file_state.dart:832: .add(new
KnownFilesSetChange(addedFiles, removedFiles));
Do we want to only add to the stream if at least one of the added and removed
sets are non-empty?

[scheglov, 2017-04-19 20:21:47]

https://codereview.chromium.org/2826243002/diff/1/pkg/analyzer/lib/src/dart/a...
File pkg/analyzer/lib/src/dart/analysis/file_state.dart (right):

https://codereview.chromium.org/2826243002/diff/1/pkg/analyzer/lib/src/dart/a...
pkg/analyzer/lib/src/dart/analysis/file_state.dart:832: .add(new
KnownFilesSetChange(addedFiles, removedFiles));
On 2017/04/19 20:09:52, Brian Wilkerson wrote:
> Do we want to only add to the stream if at least one of the added and removed
> sets are non-empty?

Yes, the intention is that we send only useful notifications.

Currently this happens implicitly, because we schedule sending notifications
only when a new file is added.

[scheglov, 2017-04-19 20:23:42]

Description was changed from

==========
Add FileSystemState.knownFilesSetChanges stream.

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

to

==========
Add FileSystemState.knownFilesSetChanges stream.

R=brianwilkerson@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/7faf4bac9373f8128d29df9f58450825cebc03d4
==========

[scheglov, 2017-04-19 20:23:43]

Committed patchset #1 (id:1) manually as
7faf4bac9373f8128d29df9f58450825cebc03d4 (presubmit successful).