bluetooth: Invalidate connection objects if a connection fails and add histograms

device/bluetooth/bluetooth_device_android.cc

Index: device/bluetooth/bluetooth_device_android.cc
diff --git a/device/bluetooth/bluetooth_device_android.cc b/device/bluetooth/bluetooth_device_android.cc
index cb142563d043a928919ff9b5dc0fc46fca2019ea..0d8664b6b5f67d50f86a926962dbdc6ad71eaa3e 100644
--- a/device/bluetooth/bluetooth_device_android.cc
+++ b/device/bluetooth/bluetooth_device_android.cc
@@ -8,6 +8,8 @@
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
+#include "base/metrics/histogram_macros.h"

[scheib, 2016/01/15 01:39:45]

Why is histogram_macros required? Seems to be a bug if it's just for
UMA_HISTOGRAM_SPARSE_SLOWLY.

[ortuno, 2016/01/15 21:34:41]

Done.

+#include "base/metrics/sparse_histogram.h"
 #include "base/strings/stringprintf.h"
 #include "device/bluetooth/bluetooth_adapter_android.h"
 #include "device/bluetooth/bluetooth_remote_gatt_service_android.h"
@@ -17,6 +19,20 @@ using base::android::AttachCurrentThread;
 using base::android::AppendJavaStringArrayToStringVector;
 
 namespace device {
+namespace {
+void RecordConnectionSuccessResult(int32_t status) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("Bluetooth.Android.GATTConnection.Success.Result",
+                              status);
+}
+void RecordConnectionFailureResult(int32_t status) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("Bluetooth.Android.GATTConnection.Failure.Result",
+                              status);
+}
+void RecordConnectionTerminatedResult(int32_t status) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY(
+      "Bluetooth.Android.GATTConnection.Terminated.Result", status);
+}
+}  // namespace
 
 BluetoothDeviceAndroid* BluetoothDeviceAndroid::Create(
     BluetoothAdapterAndroid* adapter,
@@ -206,6 +222,20 @@ void BluetoothDeviceAndroid::OnConnectionStateChange(
     const JavaParamRef<jobject>& jcaller,
     int32_t status,
     bool connected) {
+  // There are many errors not present in the Android documentation that
+  // can be returned. We histogram these errors to better understand the
+  // cases in which they arise.
+  if (connected) {
+    RecordConnectionSuccessResult(status);
+  } else if (create_gatt_connection_error_callbacks_.size() > 0) {
+    // We assume that if there are any pending connection callbacks there
+    // was a failed connection attempt.
+    RecordConnectionFailureResult(status);
+  } else {
+    // Otherwise an existing connection was terminated.
+    RecordConnectionTerminatedResult(status);
+  }
+
   gatt_connected_ = connected;
   if (gatt_connected_) {
     DidConnectGatt();