bluetooth: Add characteristicvaluechanged event

content/browser/bluetooth/bluetooth_dispatcher_host.h

Index: content/browser/bluetooth/bluetooth_dispatcher_host.h
diff --git a/content/browser/bluetooth/bluetooth_dispatcher_host.h b/content/browser/bluetooth/bluetooth_dispatcher_host.h
index 82a89230e83a8e84b7bcebce2efc7e8378277e9d..d84a8b3dc0b38462612fa856dcc7d03c27654467 100644
--- a/content/browser/bluetooth/bluetooth_dispatcher_host.h
+++ b/content/browser/bluetooth/bluetooth_dispatcher_host.h
@@ -82,6 +82,12 @@ class CONTENT_EXPORT BluetoothDispatcherHost final
       device::BluetoothGattCharacteristic* characteristic,
       const std::vector<uint8>& value) override;
 
+  // Sends an IPC to the thread informing that a the characteristic's
+  // value changed.
+  void NotifyActiveCharacteristic(int thread_id,
+                                  const std::string& characteristic_instance_id,
+                                  const std::vector<uint8>& value);
+
   // IPC Handlers, see definitions in bluetooth_messages.h.
   void OnRequestDevice(
       int thread_id,
@@ -112,6 +118,12 @@ class CONTENT_EXPORT BluetoothDispatcherHost final
   void OnStopNotifications(int thread_id,
                            int request_id,
                            const std::string& characteristic_instance_id);
+  void OnRegisterCharacteristicObject(
+      int thread_id,
+      const std::string& characteristic_instance_id);
+  void OnUnregisterCharacteristicObject(
+      int thread_id,
+      const std::string& characteristic_instance_id);
 
   // Callbacks for BluetoothAdapter::StartDiscoverySession.
   void OnDiscoverySessionStarted(
@@ -209,6 +221,11 @@ class CONTENT_EXPORT BluetoothDispatcherHost final
                      scoped_ptr<device::BluetoothGattNotifySession>>
       characteristic_id_to_notify_session_;
 
+  // Map of characteristic_instance_id to a set of thread ids.
+  // A thread_id in the set represents a BluetoothDispatcher that
+  // needs to be notified of changes to the characteristic.
+  std::map<std::string, std::set<int>> active_characteristic_threads_;
+
   // Defines how long to scan for and how long to discover services for.
   int current_delay_time_;