fix mac

tools/bbh_shootout.cpp

Index: tools/bbh_shootout.cpp
diff --git a/tools/bbh_shootout.cpp b/tools/bbh_shootout.cpp
index 682099b39fd0d7d5944ecf63365fc29872dac3c1..d86e5ffe39ce8ed3d9dff19a1535223f0c1fff8d 100644
--- a/tools/bbh_shootout.cpp
+++ b/tools/bbh_shootout.cpp
@@ -310,7 +310,8 @@ static bool benchmark_loop(
     return true;
 }
 
-static int tool_main(int argc, char** argv) {
+int tool_main(int argc, char** argv);
+int tool_main(int argc, char** argv) {
     SkAutoGraphics ag;
     SkString usage;
     usage.printf("Usage: filename [filename]*\n");
@@ -379,7 +380,10 @@ static int tool_main(int argc, char** argv) {
     return 0;
 }
 
+#if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char** argv) {
     return tool_main(argc, argv);
 }
+#endif
+