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=
Review URL: https://codereview.chromium.org/2171673002 .
Konstantin Shcheglov
fa854d41f6