bluetooth: connectGATT and receive WebBluetoothGATTRemoteServer from embedder.

Source/modules/modules.gypi

 {
   'includes': [
     '../core/core_generated.gypi',
     'modules_generated.gypi',
   ],
   'variables': {
     # Experimental hooks for embedder to provide extra IDL and source files.
     #
     # Note: this is not a supported API. If you rely on this, you will be broken
     # from time to time as the code generator changes in backward incompatible
@@ skipping 557 matching lines @@
       'beacon/NavigatorBeacon.cpp',
       'beacon/NavigatorBeacon.h',
       'bluetooth/Bluetooth.h',
       'bluetooth/BluetoothDevice.cpp',
       'bluetooth/BluetoothDevice.h',
       'bluetooth/BluetoothDiscovery.cpp',
       'bluetooth/BluetoothDiscovery.h',
       'bluetooth/BluetoothError.cpp',
       'bluetooth/BluetoothError.h',
       'bluetooth/BluetoothGATTRemoteServer.h',
+      'bluetooth/BluetoothGATTRemoteServer.cpp',
       'bluetooth/BluetoothUuids.h',
       'bluetooth/NavigatorBluetooth.cpp',
       'bluetooth/NavigatorBluetooth.h',
       'cachestorage/Cache.cpp',
       'cachestorage/Cache.h',
       'cachestorage/CacheStorage.cpp',
       'cachestorage/CacheStorage.h',
       'cachestorage/GlobalCacheStorage.cpp',
       'cachestorage/GlobalCacheStorage.h',
       'cachestorage/InspectorCacheStorageAgent.cpp',
@@ skipping 813 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }