fix build_once

still failing building goma/client
  LINK(target) out/Debug/minidump_stackwalk
out/Debug/obj.target/minidump_stackwalk/third_party/breakpad/src/processor/minid
ump.o: In function `~MinidumpContext':
/usr/local/google/home/ukai/src/goma/client/./third_party/breakpad/src/processor
/minidump.cc:419: undefined reference to `google_breakpad::DumpContext::~DumpCon
text()'
 ...
2 files changed