Currently with ViewEngine, if someone runs the platform's
`bootstrapModule` method in order to boostrap a module in
JIT mode, external component resources are properly resolved
*automatically*.
Currently with Ivy, the developer would need to manually call
`resolveComponentResources` in order to asynchronously fetch
the determined external component resources. In order to make
this backwards compatible with ViewEngine, and also since
platforms can already specify a `ResourceLoader` compiler
provider, we need to automatically resolve all external
component resources on module bootstrap.
--
Since the `ResourceLoader` is part of the `@angular/compiler`,
because ViewEngine performed the factory creation in the compiler,
we can't access the `ResourceLoader` token from within core.
In order to workaround this without introducing a breaking change,
we just proxy the `ResourceLoader` token to `core` through the
compiler facade. In the future, we should be able to move the
`ResourceLoader` to core when ViewEngine code no longer exists in
the `@angular/compiler`.
PR Close#29083
6085f335e8