bluetooth: android: register for adapter on/off events.

content/browser/bluetooth/bluetooth_dispatcher_host.cc

Index: content/browser/bluetooth/bluetooth_dispatcher_host.cc
diff --git a/content/browser/bluetooth/bluetooth_dispatcher_host.cc b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
index e5b96d93df90afdb7f89ceea2fdcf5350cc6cea2..3a8a44ef2601d9440ebc4c11e6b074da4d222081 100644
--- a/content/browser/bluetooth/bluetooth_dispatcher_host.cc
+++ b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
@@ -486,9 +486,21 @@ void BluetoothDispatcherHost::AdapterPoweredChanged(
            &request_device_sessions_);
        !iter.IsAtEnd(); iter.Advance()) {
     RequestDeviceSession* session = iter.GetCurrentValue();
+
+    // Stop ongoing discovery session if power is off.
+    if (!powered && session->discovery_session) {
+      StopDiscoverySession(std::move(session->discovery_session));
+    }
+
     if (session->chooser)
       session->chooser->SetAdapterPresence(presence);
   }
+
+  // Stop the timer so that we don't change the state of the chooser
+  // when timer expires.
+  if (!powered) {
+    discovery_session_timer_.Stop();
+  }
 }
 
 void BluetoothDispatcherHost::DeviceAdded(device::BluetoothAdapter* adapter,