In a future change, crashpad_util_test_lib will gain a dependency on
crashpad_client. This would violate GYP’s prohibition on circular
dependencies between .gyp files, although there would be no circular
relationship between the targets themselves. To overcome this problem,
all test-related targets are moved into their own first-class .gyp
files.
BUG=crashpad:33
R=scottmg@chromium.org
Review URL: https://codereview.chromium.org/1045173004
