According to the comment in logging.h, Vlog level of foo.{h,cc} should be set to X, when --vmodule="foo=X."
https://cs.chromium.org/chromium/src/base/logging.h?q=vmodule&dr=C&l=91

However, the log level isn't X, but the default max vlog level (= 0).

The below is the example of a failed test case.
You can confirm reproducing by pasting in vlog_unittest.cc

"""
TEST(VlogTest, VmoduleBasic2) {
  const char kVSwitch[] = "-1";
  const char kVModuleSwitch[] =
      "/path/to/*foo=1";
  int min_log_level = 0;
  VlogInfo vlog_info(kVSwitch, kVModuleSwitch, &min_log_level);
  EXPECT_EQ(1, vlog_info.GetVlogLevel("/path/to/foo.cc"));
}
"""