Make unit_tests compile in Mac GN

chrome/utility/BUILD.gn

Index: chrome/utility/BUILD.gn
diff --git a/chrome/utility/BUILD.gn b/chrome/utility/BUILD.gn
index 8bda50aa87267a2278edd5f359f8b3e39df04c45..4777889d9db3df0607a15f25b4f581596a4f9ddc 100644
--- a/chrome/utility/BUILD.gn
+++ b/chrome/utility/BUILD.gn
@@ -4,16 +4,25 @@
 
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
+import("//build/config/sysroot.gni")
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("../chrome_utility.gypi") ],
                           "scope",
                           [ "../chrome_utility.gypi" ])
 
+# Provides a way for the utility library to push ldflags to dependents.
+config("utility_ldflags") {
+  if (is_mac && safe_browsing_mode == 1) {
+    ldflags = [ "/usr/lib/libbz2.dylib" ]
+  }
+}
+
 static_library("utility") {
   sources = rebase_path(gypi_values.chrome_utility_sources, ".", "..")
   defines = []
   configs += [ "//build/config:precompiled_headers" ]
+  all_dependent_configs = [ ":utility_ldflags" ]
 
   public_deps = []
   deps = [