This CL mainly changes:
a) moving the interface in struct provider_vtab to std::function;
b) code cleanup, such as moving the declaration closer to the uses,
using explicit type conversion.
Test: recovery_component_test
Test: minadbd_test
Test: Sideload a package on marlin.
Change-Id: Id0e3c70f1ada54a4cd985b54c84438c23ed4687e
Split the adb-specific portions (fetching a block from the adb host
and closing the connections) out from the rest of the FUSE filesystem
code, so that we can reuse the fuse stuff for installing off sdcards
as well.
Change-Id: I0ba385fd35999c5f5cad27842bc82024a264dd14
