UMA log for audio_device Init and Start(Playout|Recording). Make Init return a more specific error …

webrtc/system_wrappers/include/metrics.h

Index: webrtc/system_wrappers/include/metrics.h
diff --git a/webrtc/system_wrappers/include/metrics.h b/webrtc/system_wrappers/include/metrics.h
index d5e549285fa33aecd054819e9753f3d17a590006..0fee344aa407ac295861ece924f56486b5fff553 100644
--- a/webrtc/system_wrappers/include/metrics.h
+++ b/webrtc/system_wrappers/include/metrics.h
@@ -125,6 +125,14 @@
 #define RTC_LOGGED_HISTOGRAM_PERCENTAGE(name, sample) \
   RTC_LOGGED_HISTOGRAM_ENUMERATION(name, sample, 101)
 
+// Histogram for booleans.
+#define RTC_HISTOGRAM_BOOLEAN(name, sample) \
+  RTC_HISTOGRAM_ENUMERATION(name, sample, 2)
+
+// RTC_HISTOGRAM_BOOLEAN with logging.
+#define RTC_LOGGED_HISTOGRAM_BOOLEAN(name, sample) \
+  RTC_LOGGED_HISTOGRAM_ENUMERATION(name, sample, 2)
+
 // Histogram for enumerators (evenly spaced buckets).
 // |boundary| should be above the max enumerator sample.
 #define RTC_HISTOGRAM_ENUMERATION(name, sample, boundary) \