small fix for BUILD.gn

crash_key.h includes components/crash/core/common/crash_buildflags.h,
so action target generating crash_buildflags.h needs to be in
public_deps.

See below reference for more details.
https://gn.googlesource.com/gn/+/master/docs/reference.md#var_public_deps

Bug: 931596
Change-Id: Idcf871bfd62b6684b97dbb0e834b022518a157cd
Reviewed-on: https://chromium-review.googlesource.com/c/1469855
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631724}
1 file changed