arc: bluetooth: Add/Remove BT observer only when ARC is ready

components/arc/bluetooth/arc_bluetooth_bridge.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/arc/bluetooth/arc_bluetooth_bridge.h"
 
 #include <bluetooth/bluetooth.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <sys/socket.h>
@@ skipping 161 matching lines @@
 bool IsGattOffsetValid(int offset) {
   return 0 <= offset && offset < kMaxGattAttributeLength;
 }
 
 }  // namespace
 
 namespace arc {
 
 ArcBluetoothBridge::ArcBluetoothBridge(ArcBridgeService* bridge_service)
     : ArcService(bridge_service), binding_(this), weak_factory_(this) {
-  if (BluetoothAdapterFactory::IsBluetoothAdapterAvailable()) {
-    VLOG(1) << "registering bluetooth adapter";
-    BluetoothAdapterFactory::GetAdapter(base::Bind(
-        &ArcBluetoothBridge::OnAdapterInitialized, weak_factory_.GetWeakPtr()));
-  } else {
-    VLOG(1) << "no bluetooth adapter available";
-  }
-
   arc_bridge_service()->bluetooth()->AddObserver(this);
 }
 
 ArcBluetoothBridge::~ArcBluetoothBridge() {
   DCHECK(CalledOnValidThread());
 
   arc_bridge_service()->bluetooth()->RemoveObserver(this);
 
   if (bluetooth_adapter_)
     bluetooth_adapter_->RemoveObserver(this);
 }
 
 void ArcBluetoothBridge::OnAdapterInitialized(
     scoped_refptr<BluetoothAdapter> adapter) {
   DCHECK(CalledOnValidThread());
 
   // We can downcast here because we are always running on Chrome OS, and
   // so our adapter uses BlueZ.
   bluetooth_adapter_ =
       static_cast<bluez::BluetoothAdapterBlueZ*>(adapter.get());
   bluetooth_adapter_->AddObserver(this);
+  bluetooth_observer_flag_ = true;
 }
 
 void ArcBluetoothBridge::OnInstanceReady() {
   mojom::BluetoothInstance* bluetooth_instance =
       arc_bridge_service()->bluetooth()->instance();
   if (!bluetooth_instance) {
     LOG(ERROR) << "OnBluetoothInstanceReady called, "
                << "but no bluetooth instance found";
     return;
   }
   bluetooth_instance->Init(binding_.CreateInterfacePtrAndBind());
+  if (BluetoothAdapterFactory::IsBluetoothAdapterAvailable()) {
+    VLOG(1) << "registering bluetooth adapter";

[rkc, 2016/08/08 21:08:12]

VLOG(1) << "Registering Bluetooth adapter.";

[puthik_chromium, 2016/08/08 21:40:25]

Done.

+    BluetoothAdapterFactory::GetAdapter(base::Bind(
+        &ArcBluetoothBridge::OnAdapterInitialized, weak_factory_.GetWeakPtr()));
+  } else {
+    VLOG(1) << "no bluetooth adapter available";

[rkc, 2016/08/08 21:08:12]

VLOG(1) << "No Bluetooth adapter available.";

[puthik_chromium, 2016/08/08 21:40:25]

Done.

+  }
+}
+
+void ArcBluetoothBridge::OnInstanceClosed() {
+  if (bluetooth_observer_flag_ && bluetooth_adapter_)
+    bluetooth_adapter_->RemoveObserver(this);

[rkc, 2016/08/08 21:08:12]

You don't need the bluetooth_observer_flag_ flag. If there is no observer
registered, RemoveObserver will do nothing.

[puthik_chromium, 2016/08/08 21:40:25]

The flag is used to see that we should register observer when bluetooth_adapter_
is ready or when arc_instance is ready. 

+  bluetooth_observer_flag_ = false;
 }
 
 void ArcBluetoothBridge::AdapterPoweredChanged(BluetoothAdapter* adapter,
                                                bool powered) {
   if (!HasBluetoothInstance())
     return;
 
   // TODO(smbarber): Invoke EnableAdapter or DisableAdapter via ARC bridge
   // service.
 }
@@ skipping 1408 matching lines @@
   LOG(WARNING) << "Bluetooth instance is too old (version " << version
                << ") need version " << version_need;
   return false;
 }
 
 bool ArcBluetoothBridge::CalledOnValidThread() {
   return thread_checker_.CalledOnValidThread();
 }
 
 }  // namespace arc