gfx_unittests builds on 10.13

ui/gfx/icc_profile_mac.mm

Index: ui/gfx/icc_profile_mac.mm
diff --git a/ui/gfx/icc_profile_mac.mm b/ui/gfx/icc_profile_mac.mm
index 1aa768cc699f79ef837737d921c31454e0052dbb..05875011dbaa32d1944935b180965ff44e1385e4 100644
--- a/ui/gfx/icc_profile_mac.mm
+++ b/ui/gfx/icc_profile_mac.mm
@@ -19,8 +19,10 @@ ICCProfile ICCProfile::FromCGColorSpace(CGColorSpaceRef cg_color_space) {
   if (HasForcedProfile())
     return GetForcedProfile();
 
-  base::ScopedCFTypeRef<CFDataRef> cf_icc_profile(
-      CGColorSpaceCopyICCProfile(cg_color_space));
+  base::ScopedCFTypeRef<CFDataRef> cf_icc_profile;
+  if (__builtin_available(macOS 10.12, *)) {
+    cf_icc_profile.reset(CGColorSpaceCopyICCProfile(cg_color_space));
+  }
   if (!cf_icc_profile)
     return gfx::ICCProfile();
   size_t length = CFDataGetLength(cf_icc_profile);
@@ -31,3 +33,11 @@ ICCProfile ICCProfile::FromCGColorSpace(CGColorSpaceRef cg_color_space) {
 }
 
 }  // namespace gfx
+
+extern "C" {
+
+// This does not belong here..
+int32_t __isOSVersionAtLeast(int32_t Major, int32_t Minor, int32_t Subminor) {
+  return 0;
+}
+}