mac: Add metrics to record Bluetooth availability and capabilities.

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

Index: chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
diff --git a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
index bd9ccf2d2648d65e0628141b68d500fc0e764480..e759a6d786d5eb4a8e3b60963299253c39bc0f84 100644
--- a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
+++ b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
@@ -18,6 +18,7 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/chrome_browser_metrics_service_observer.h"
+#include "chrome/browser/mac/hardware_utility.h"
 #include "chrome/browser/pref_service_flags_storage.h"
 #include "chrome/browser/shell_integration.h"
 #include "content/public/browser/browser_thread.h"
@@ -94,6 +95,14 @@ void RecordStartupMetricsOnBlockingPool() {
 #if defined(OS_WIN)
   GoogleUpdateSettings::RecordChromeUpdatePolicyHistograms();
 #endif  // defined(OS_WIN)
+
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  hardware_utility::BluetoothAvailability availability =
+      hardware_utility::GetBluetoothAvailability();
+  UMA_HISTOGRAM_ENUMERATION("OSX.BluetoothAvailability",
+                            availability,
+                            hardware_utility::BLUETOOTH_AVAILABILITY_COUNT);

[Ilya Sherman, 2014/07/09 21:19:33]

I might be mistaken, but I don't think that the bluetooth system is threadsafe. 
Are you sure that it's ok to query bluetooth state from the blocking pool's
thread?

[Ilya Sherman, 2014/07/09 21:19:33]

By the way, note that there is a Bluetooth section in the system_profile.proto
message definition.  I think that's currently only filled out on ChromeOS, and
the histogram is probably more convenient to work with, but still... FYI.

[erikchen, 2014/07/11 17:25:44]

We're not touching the bluetooth system, we're touching IOKit, which should be
fine.

[erikchen, 2014/07/11 17:25:44]

As per offline discussion, I am keeping this a histogram.

+#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 }
 
 void RecordLinuxGlibcVersion() {