Implement BroadcastChannel

third_party/WebKit/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
     # ways.
     'extra_blink_module_idl_files': [],
     'extra_blink_module_files': [],
     # Files for which bindings (.cpp and .h files) will be generated
     'modules_idl_files': [
       '<@(extra_blink_module_idl_files)',
       'app_banner/AppBannerPromptResult.idl',
       'app_banner/BeforeInstallPromptEvent.idl',
       'background_sync/SyncEvent.idl',
       'background_sync/SyncManager.idl',
       'battery/BatteryManager.idl',
       'bluetooth/Bluetooth.idl',
       'bluetooth/BluetoothDevice.idl',
       'bluetooth/BluetoothCharacteristicProperties.idl',
       'bluetooth/BluetoothRemoteGATTCharacteristic.idl',
       'bluetooth/BluetoothRemoteGATTServer.idl',
       'bluetooth/BluetoothRemoteGATTService.idl',
       'bluetooth/BluetoothUUID.idl',
+      'broadcastchannel/BroadcastChannel.idl',
       'cachestorage/Cache.idl',
       'cachestorage/CacheStorage.idl',
       'canvas2d/CanvasGradient.idl',
       'canvas2d/CanvasPattern.idl',
       'canvas2d/CanvasRenderingContext2D.idl',
       'canvas2d/Path2D.idl',
       'compositorworker/CompositorWorker.idl',
       'compositorworker/CompositorWorkerGlobalScope.idl',
       'credentialmanager/Credential.idl',
       'credentialmanager/CredentialsContainer.idl',
@@ skipping 812 matching lines @@
       'bluetooth/BluetoothRemoteGATTServer.cpp',
       'bluetooth/BluetoothRemoteGATTServer.h',
       'bluetooth/BluetoothRemoteGATTService.cpp',
       'bluetooth/BluetoothRemoteGATTService.h',
       'bluetooth/BluetoothSupplement.cpp',
       'bluetooth/BluetoothSupplement.h',
       'bluetooth/BluetoothUUID.cpp',
       'bluetooth/BluetoothUUID.h',
       'bluetooth/NavigatorBluetooth.cpp',
       'bluetooth/NavigatorBluetooth.h',
+      'broadcastchannel/BroadcastChannel.cpp',
+      'broadcastchannel/BroadcastChannel.h',
       'cachestorage/Cache.cpp',
       'cachestorage/Cache.h',
       'cachestorage/CacheStorage.cpp',
       'cachestorage/CacheStorage.h',
       'cachestorage/CacheStorageError.cpp',
       'cachestorage/CacheStorageError.h',
       'cachestorage/GlobalCacheStorage.cpp',
       'cachestorage/GlobalCacheStorage.h',
       'cachestorage/InspectorCacheStorageAgent.cpp',
       'cachestorage/InspectorCacheStorageAgent.h',
@@ skipping 1124 matching lines @@
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'webdatabase/QuotaTrackerTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }