NativeStackSampler implementation for Mac.

chrome/common/stack_sampling_configuration.cc

Index: chrome/common/stack_sampling_configuration.cc
diff --git a/chrome/common/stack_sampling_configuration.cc b/chrome/common/stack_sampling_configuration.cc
index c2b0786442b1541f0c0f2ec144f5b300a16f3585..36ff7cc7458e7ba351874dd686da1d856373ce08 100644
--- a/chrome/common/stack_sampling_configuration.cc
+++ b/chrome/common/stack_sampling_configuration.cc
@@ -7,6 +7,7 @@
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/rand_util.h"
+#include "build/build_config.h"
 #include "chrome/common/channel_info.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/version_info/version_info.h"
@@ -17,16 +18,23 @@ namespace {
 base::LazyInstance<StackSamplingConfiguration>::Leaky g_configuration =
     LAZY_INSTANCE_INITIALIZER;
 
-// The profiler is currently only implemented for Windows x64, and only runs on
-// trunk, canary, and dev.
+// The profiler is currently only implemented for Windows x64 and Mac x64.
 bool IsProfilerSupported() {
-#if !defined(_WIN64)
-  return false;
-#else
+#if defined(OS_WIN)

[Mike Wittman, 2017/03/27 19:48:46]

#if defined(OS_WIN) && defined(ARCH_CPU_X86_64)

[Avi (use Gerrit), 2017/03/29 17:52:09]

Done.

+  // Only run on trunk, canary, and dev.
   const version_info::Channel channel = chrome::GetChannel();

[Mike Wittman, 2017/03/27 19:48:46]

Can we do this so we have the same approach wrt the unknown channel:

#if defined(GOOGLE_CHROME_BUILD)
const version_info::Channel channel = chrome::GetChannel();
return channel == version_info::Channel::CANARY ||
    channel == version_info::Channel::DEV;
#else
return true;
#endif

[Avi (use Gerrit), 2017/03/29 17:52:09]

Done.

-  return (channel == version_info::Channel::UNKNOWN ||
-          channel == version_info::Channel::CANARY ||
-          channel == version_info::Channel::DEV);
+  return channel == version_info::Channel::UNKNOWN ||
+         channel == version_info::Channel::CANARY ||
+         channel == version_info::Channel::DEV;
+#elif defined(OS_MACOSX)
+  // This is experimental, so only run on trunk.
+  #if defined(GOOGLE_CHROME_BUILD)

[Mike Wittman, 2017/03/20 19:21:30]

Can you apply the same change to the OS_WIN section, for consistency?

[Avi (use Gerrit), 2017/03/27 16:06:30]

Done.

+    return false;
+  #else
+    return true;
+  #endif
+#else
+  return false;
 #endif
 }