[Clean up] Introduce a BLUETOOTH_EXPORT macro to control symbol visibility outside of //device/blue…

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 4557f3b5e0b795ca221ddea8f3ceaf08603c94e2..54c5ed4a4b8e8a96c5a12974410d2bfa0216845b 100644
--- a/device/bluetooth/bluetooth_device.h
+++ b/device/bluetooth/bluetooth_device.h
@@ -13,6 +13,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/string16.h"
+#include "device/bluetooth/bluetooth_export.h"
 #include "device/bluetooth/bluetooth_uuid.h"
 #include "net/base/net_log.h"
 
@@ -34,7 +35,7 @@ class BluetoothUUID;
 // Since the lifecycle of BluetoothDevice instances is managed by
 // BluetoothAdapter, that class rather than this provides observer methods
 // for devices coming and going, as well as properties being updated.
-class BluetoothDevice {
+class BLUETOOTH_EXPORT BluetoothDevice {
  public:
   // Possible values that may be returned by GetVendorIDSource(),
   // indicating different organisations that allocate the identifiers returned