Fix getting notified twice after subscribe to notifications and call readValue

device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h

Index: device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h
diff --git a/device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h b/device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h
index 0687b0d2d31788a2877e4e74f1497ced97baffa3..c25c22fab5ce256904bb47084a8badaf2ba13e0b 100644
--- a/device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h
+++ b/device/bluetooth/bluez/bluetooth_remote_gatt_characteristic_bluez.h
@@ -63,6 +63,14 @@ class BluetoothRemoteGattCharacteristicBlueZ
                                  const base::Closure& callback,
                                  const ErrorCallback& error_callback) override;
 
+  bool characteristic_value_read_in_progress() {
+    return characteristic_value_read_in_progress_;
+  }
+
+  void set_characteristic_value_read_in_progress(bool in_progress) {
+    characteristic_value_read_in_progress_ = in_progress;
+  }
+
  protected:
   void SubscribeToNotifications(
       device::BluetoothRemoteGattDescriptor* ccc_descriptor,
@@ -110,11 +118,17 @@ class BluetoothRemoteGattCharacteristicBlueZ
                          const std::string& error_name,
                          const std::string& error_message);
 
-  // Called by dbus:: on unsuccessful completion of a request to read or write
+  // Called by dbus:: on unsuccessful completion of a request to read
   // the characteristic value.
-  void OnError(const ErrorCallback& error_callback,
-               const std::string& error_name,
-               const std::string& error_message);
+  void OnReadError(const ErrorCallback& error_callback,
+                   const std::string& error_name,
+                   const std::string& error_message);
+
+  // Called by dbus:: on unsuccessful completion of a request to write
+  // the characteristic value.
+  void OnWriteError(const ErrorCallback& error_callback,
+                    const std::string& error_name,
+                    const std::string& error_message);
 
   // True, if there exists a Bluez notify session.
   bool has_notify_session_;
@@ -133,6 +147,9 @@ class BluetoothRemoteGattCharacteristicBlueZ
   // The GATT service this GATT characteristic belongs to.
   BluetoothRemoteGattServiceBlueZ* service_;
 
+  // True if a gatt read request is in progress.
+  bool characteristic_value_read_in_progress_;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<BluetoothRemoteGattCharacteristicBlueZ>