fuchsia: Add missing transformer.cc to fidl_base
fuchsia: Add missing transformer.cc to fidl_base

Fix fidl_base build, again. Fixes broken tryjobs as seen in
https://chromium-review.googlesource.com/c/crashpad/crashpad/+/1872188.

Change-Id: Iaec1613b3b335fac501227b7a86134309f52d7f3
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/1899650
Reviewed-by: Francois Rousseau <abdb75be6d92482eb3ea75e9341306a6fcc3aacd@google.com>
Commit-Queue: Scott Graham <e134406e1863f3b48b0795831afac5c0595efb36@chromium.org>

chromium/crashpad,chromium/crashpad,chromium/crashpad