Stack sampling profiler to profile on Mac. TEST-- not for commit.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index aa9261df467ae3255860fed980232ae9c8b3ab2d..c7af37370d3d342aecf641f121ac3c1710eaf59d 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -396,6 +396,7 @@ component("base") {
     "profiler/alternate_timer.h",
     "profiler/native_stack_sampler.cc",
     "profiler/native_stack_sampler.h",
+    "profiler/native_stack_sampler_mac.cc",
     "profiler/native_stack_sampler_posix.cc",
     "profiler/native_stack_sampler_win.cc",
     "profiler/scoped_profile.cc",
@@ -822,6 +823,10 @@ component("base") {
       "threading/platform_thread_internal_posix.cc",
     ]
 
+    if (is_mac) {
+      sources -= [ "profiler/native_stack_sampler_posix.cc" ]
+    }
+
     if (is_asan) {
       # TODO(GYP) hook up asan on Mac. GYP has this extra dylib:
       #data += [ "$root_out_dir/libclang_rt.asan_osx_dynamic.dylib" ]