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

device/bluetooth/bluetooth.gyp

Index: device/bluetooth/bluetooth.gyp
diff --git a/device/bluetooth/bluetooth.gyp b/device/bluetooth/bluetooth.gyp
index d6b8c7e95a61108dd9d6a905c8a1ed8d7577a278..ccc3832a19c9974f0d802799b25a7cfecb217242 100644
--- a/device/bluetooth/bluetooth.gyp
+++ b/device/bluetooth/bluetooth.gyp
@@ -10,7 +10,7 @@
     {
       # GN version: //device/bluetooth
       'target_name': 'device_bluetooth',
-      'type': 'static_library',
+      'type': '<(component)',
       'dependencies': [
         '../../base/base.gyp:base',
         '../../net/net.gyp:net',
@@ -43,6 +43,7 @@
         'bluetooth_discovery_manager_mac.h',
         'bluetooth_discovery_session.cc',
         'bluetooth_discovery_session.h',
+        'bluetooth_export.h',
         'bluetooth_gatt_characteristic.cc',
         'bluetooth_gatt_characteristic.h',
         'bluetooth_gatt_connection.cc',
@@ -94,6 +95,9 @@
         'bluetooth_uuid.cc',
         'bluetooth_uuid.h',
       ],
+      'defines': [
+        'BLUETOOTH_IMPLEMENTATION',
+      ],
       'conditions': [
         ['chromeos==1', {
           'dependencies': [