Implement the NativeStackSampler for the Mac.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index cf3d3058900bf362101f226b7a18e705f50b1572..63af434be4379837249fa02a54497a91fa0fad66 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -693,6 +693,7 @@ component("base") {
     "process/process_win.cc",
     "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",
@@ -1469,6 +1470,10 @@ component("base") {
       "strings/sys_string_conversions_posix.cc",
       "threading/platform_thread_internal_posix.cc",
     ]
+
+    if (is_mac) {
+      sources -= [ "profiler/native_stack_sampler_posix.cc" ]
+    }
   } else {
     # Non-Mac/ios.
     sources -= [
@@ -1840,7 +1845,9 @@ if (is_win) {
       "//base/win:base_win_features",
     ]
   }
+}
 
+if (is_win || is_mac) {
   if (current_cpu == "x64") {
     # Must be a shared library so that it can be unloaded during testing.
     shared_library("base_profiler_test_support_library") {
@@ -2304,6 +2311,9 @@ test("base_unittests") {
       "CoreFoundation.framework",
       "Foundation.framework",
     ]
+    if (current_cpu == "x64") {
+      data_deps += [ ":base_profiler_test_support_library" ]
+    }
   }
 
   if (is_linux) {
@@ -2342,7 +2352,7 @@ test("base_unittests") {
     deps += [ "//base:scoped_handle_test_dll" ]
     if (current_cpu == "x64") {
       sources += [ "profiler/win32_stack_frame_unwinder_unittest.cc" ]
-      deps += [ ":base_profiler_test_support_library" ]
+      data_deps += [ ":base_profiler_test_support_library" ]
     }
   }