Fix for limited invalidation in the middle, and the unlimited invalidation for an exported library.

Fix for limited invalidation in the middle, and the unlimited invalidation for an exported library.

Consider libraries `A`, `B`, and `C`, where `C` imports `B`, and `B`
exports `A`. [RESOLVED_UNIT4] of `C` depends on [LIBRARY_ELEMENT4] of
[IMPORTED_LIBRARIES], i.e. `B`. Even though [LIBRARY_ELEMENT4] of `B`
depends on [LIBRARY_ELEMENT3]s of its [EXPORT_SOURCE_CLOSURE] (i.e. `A`
and `B`), [RESOLVED_UNIT4] of `C` sees only [LIBRARY_ELEMENT4] of `B`.

When invalidate results of `B` (but keep results of `C`), we will
invalidate and remove [LIBRARY_ELEMENT4] of `B`, so we lose knowledge
that [RESOLVED_UNIT4] of `C` indirectly depends on `A`.

The solution is do depend on [EXPORT_SOURCE_CLOSURE] of all
[IMPORTED_LIBRARIES] in [RESOLVED_UNIT4] of `C`.

R=brianwilkerson@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/fa854d41f6eec36d4c31ab8a6d92fbc48c68e593

[Brian Wilkerson, 2016-07-21 13:50:41]

lgtm

[scheglov, 2016-07-21 14:26:51]

Description was changed from

==========
Fix for limited invalidation in the middle, and the unlimited invalidation for
an exported library.

Consider libraries `A`, `B`, and `C`, where `C` imports `B`, and `B`
exports `A`. [RESOLVED_UNIT4] of `C` depends on [LIBRARY_ELEMENT4] of
[IMPORTED_LIBRARIES], i.e. `B`. Even though [LIBRARY_ELEMENT4] of `B`
depends on [LIBRARY_ELEMENT3]s of its [EXPORT_SOURCE_CLOSURE] (i.e. `A`
and `B`), [RESOLVED_UNIT4] of `C` sees only [LIBRARY_ELEMENT4] of `B`.

When invalidate results of `B` (but keep results of `C`), we will
invalidate and remove [LIBRARY_ELEMENT4] of `B`, so we lose knowledge
that [RESOLVED_UNIT4] of `C` indirectly depends on `A`.

The solution is do depend on [EXPORT_SOURCE_CLOSURE] of all
[IMPORTED_LIBRARIES] in [RESOLVED_UNIT4] of `C`.

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

to

==========
Fix for limited invalidation in the middle, and the unlimited invalidation for
an exported library.

Consider libraries `A`, `B`, and `C`, where `C` imports `B`, and `B`
exports `A`. [RESOLVED_UNIT4] of `C` depends on [LIBRARY_ELEMENT4] of
[IMPORTED_LIBRARIES], i.e. `B`. Even though [LIBRARY_ELEMENT4] of `B`
depends on [LIBRARY_ELEMENT3]s of its [EXPORT_SOURCE_CLOSURE] (i.e. `A`
and `B`), [RESOLVED_UNIT4] of `C` sees only [LIBRARY_ELEMENT4] of `B`.

When invalidate results of `B` (but keep results of `C`), we will
invalidate and remove [LIBRARY_ELEMENT4] of `B`, so we lose knowledge
that [RESOLVED_UNIT4] of `C` indirectly depends on `A`.

The solution is do depend on [EXPORT_SOURCE_CLOSURE] of all
[IMPORTED_LIBRARIES] in [RESOLVED_UNIT4] of `C`.

R=brianwilkerson@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/fa854d41f6eec36d4c31ab8a6d92fbc48c68e593
==========

[scheglov, 2016-07-21 14:26:52]

Committed patchset #2 (id:20001) manually as
fa854d41f6eec36d4c31ab8a6d92fbc48c68e593 (presubmit successful).