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

webrtc/modules/audio_device/linux/audio_device_alsa_linux.cc

Index: webrtc/modules/audio_device/linux/audio_device_alsa_linux.cc
diff --git a/webrtc/modules/audio_device/linux/audio_device_alsa_linux.cc b/webrtc/modules/audio_device/linux/audio_device_alsa_linux.cc
index bdbccde05012ec35cd71048008e5a0182216fa57..279900654f64264e0ab8764bfb53c7b5f0bdee16 100644
--- a/webrtc/modules/audio_device/linux/audio_device_alsa_linux.cc
+++ b/webrtc/modules/audio_device/linux/audio_device_alsa_linux.cc
@@ -155,25 +155,21 @@ int32_t AudioDeviceLinuxALSA::ActiveAudioLayer(
     return 0;
 }
 
-int32_t AudioDeviceLinuxALSA::Init()
-{
-
-    CriticalSectionScoped lock(&_critSect);
+AudioDeviceGeneric::InitStatus AudioDeviceLinuxALSA::Init() {
+  CriticalSectionScoped lock(&_critSect);
 
-    // Load libasound
-    if (!AlsaSymbolTable.Load())
-    {
-        // Alsa is not installed on
-        // this system
-        WEBRTC_TRACE(kTraceError, kTraceAudioDevice, _id,
-                   "  failed to load symbol table");
-        return -1;
-    }
+  // Load libasound
+  if (!AlsaSymbolTable.Load()) {
+    // Alsa is not installed on
+    // this system
+    WEBRTC_TRACE(kTraceError, kTraceAudioDevice, _id,
+                 "  failed to load symbol table");
+    return InitStatus::kOtherError;
+  }
 
-    if (_initialized)
-    {
-        return 0;
-    }
+  if (_initialized) {
+    return InitStatus::kOk;
+  }
 #if defined(USE_X11)
     //Get X display handle for typing detection
     _XDisplay = XOpenDisplay(NULL);
@@ -190,7 +186,7 @@ int32_t AudioDeviceLinuxALSA::Init()
 
     _initialized = true;
 
-    return 0;
+    return InitStatus::kOk;
 }
 
 int32_t AudioDeviceLinuxALSA::Terminate()