bluetooth: android: Implement & test CreateGattConnection.

device/bluetooth/bluetooth_device.h

Index: device/bluetooth/bluetooth_device.h
diff --git a/device/bluetooth/bluetooth_device.h b/device/bluetooth/bluetooth_device.h
index e548007c206da790d35f3104e4bc41b4c70a3aa8..1fed2155cecaf7039e56acde634c55dbe1233f77 100644
--- a/device/bluetooth/bluetooth_device.h
+++ b/device/bluetooth/bluetooth_device.h
@@ -11,6 +11,7 @@
 #include <vector>
 
 #include "base/callback.h"
+#include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "device/bluetooth/bluetooth_export.h"
@@ -435,6 +436,14 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothDevice {
  protected:
   // BluetoothGattConnection is a friend to call Add/RemoveGattConnection.
   friend BluetoothGattConnection;
+  FRIEND_TEST_ALL_PREFIXES(
+      BluetoothTest,
+      BluetoothGattConnection_DisconnectGatt_SimulateConnect);
+  FRIEND_TEST_ALL_PREFIXES(
+      BluetoothTest,
+      BluetoothGattConnection_DisconnectGatt_SimulateDisconnect);
+  FRIEND_TEST_ALL_PREFIXES(BluetoothTest,
+                           BluetoothGattConnection_ErrorAfterConnection);
 
   BluetoothDevice(BluetoothAdapter* adapter);