Fix mac build

Change-Id: Ie23fb9d5ab35031e3756f79569ba767a75109d64
diff --git a/BUILD.gn b/BUILD.gn
index 4995177..766afbb 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -29,10 +29,12 @@
     "src/ipc/protoc_plugin:ipc_plugin($host_toolchain)",
     "src/protozero/protoc_plugin($host_toolchain)",
     "tools/dump_process_data",
-    "tools/ftrace_proto_gen:ftrace_proto_gen",
     "tools/proto_to_cpp",
     "tools/trace_to_text",
   ]
+  if (is_linux || is_android) {
+    deps += [ "tools/ftrace_proto_gen:ftrace_proto_gen" ]
+  }
   if (!build_with_chromium) {
     deps += [
       "protos/perfetto/config:merged_config",  # For syntax-checking the proto.
@@ -57,12 +59,16 @@
     "gn:default_deps",
     "gn:gtest_main",
     "src/base:base_unittests",
-    "src/ftrace_reader:ftrace_reader_unittests",
     "src/ipc:perfetto_ipc_unittests",
     "src/protozero:protozero_unittests",
     "src/tracing:tracing_unittests",
-    "tools/ftrace_proto_gen:ftrace_proto_gen_unittests",
   ]
+  if (is_linux || is_android) {
+    deps += [
+      "src/ftrace_reader:ftrace_reader_unittests",
+      "tools/ftrace_proto_gen:ftrace_proto_gen_unittests",
+    ]
+  }
   if (!build_with_chromium) {
     deps += [ "tools/sanitizers_unittests" ]
   }