Make smbfs.mojom a public dep of //chromeos/components/smbfs:smbfs

Constants defined in the mojom are re-exported as part of the public
API. Adding the mojom as a public dep ensures the header files are
generated before trying to compile any dependent target.

Bug: 939235
Change-Id: I80b72bcf2ab7a722ebdd3c6c2703fbb546affad9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2037298Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Anand Mistry <amistry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738407}

chromeos/components/smbfs/BUILD.gn

@@ -11,10 +11,10 @@ component("smbfs") {
     "smbfs_mounter.cc",
     "smbfs_mounter.h",
   ]
+  public_deps = [ "//chromeos/components/smbfs/mojom" ]
   deps = [
     "//base",
     "//chromeos/components/mojo_bootstrap",
-    "//chromeos/components/smbfs/mojom",
     "//chromeos/disks",
     "//mojo/public/cpp/bindings",
     "//net",