Add USBConnectionEvent to webusb module.

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 276 matching lines @@
       'webmidi/MIDIMessageEvent.idl',
       'webmidi/MIDIOutput.idl',
       'webmidi/MIDIOutputMap.idl',
       'webmidi/MIDIPort.idl',
       'websockets/CloseEvent.idl',
       'websockets/WebSocket.idl',
       'webusb/USB.idl',
       'webusb/USBAlternateInterface.idl',
       'webusb/USBEndpoint.idl',
       'webusb/USBConfiguration.idl',
+      'webusb/USBConnectionEvent.idl',
       'webusb/USBDevice.idl',
       'webusb/USBInterface.idl',
     ],
     # 'partial interface' or target (right side of) 'implements'
     'modules_dependency_idl_files': [
       'audio_output_devices/HTMLMediaElementAudioOutputDevice.idl',
       'background_sync/ServiceWorkerGlobalScopeSync.idl',
       'background_sync/ServiceWorkerRegistrationSync.idl',
       'battery/NavigatorBattery.idl',
       'beacon/NavigatorBeacon.idl',
@@ skipping 160 matching lines @@
       'speech/SpeechRecognitionErrorInit.idl',
       'speech/SpeechRecognitionEventInit.idl',
       'storage/StorageEventInit.idl',
       'vr/VRFieldOfViewInit.idl',
       'webgl/WebGLContextAttributes.idl',
       'webgl/WebGLContextEventInit.idl',
       'webmidi/MIDIConnectionEventInit.idl',
       'webmidi/MIDIMessageEventInit.idl',
       'webmidi/MIDIOptions.idl',
       'websockets/CloseEventInit.idl',
+      'webusb/USBConnectionEventInit.idl',
       'webusb/USBDeviceRequestOptions.idl',
       'webusb/USBDeviceFilter.idl',
     ],
     'generated_modules_files': [
       # .cpp files from make_modules_generated actions.
       '<(blink_modules_output_dir)/EventModules.cpp',
       '<(blink_modules_output_dir)/EventModulesHeaders.h',
       '<(blink_modules_output_dir)/EventModulesNames.cpp',
       '<(blink_modules_output_dir)/EventModulesNames.h',
       '<(blink_modules_output_dir)/EventTargetModulesNames.cpp',
@@ skipping 121 matching lines @@
       '<(blink_modules_output_dir)/webgl/WebGLContextEventInit.cpp',
       '<(blink_modules_output_dir)/webgl/WebGLContextEventInit.h',
       '<(blink_modules_output_dir)/webmidi/MIDIConnectionEventInit.cpp',
       '<(blink_modules_output_dir)/webmidi/MIDIConnectionEventInit.h',
       '<(blink_modules_output_dir)/webmidi/MIDIMessageEventInit.h',
       '<(blink_modules_output_dir)/webmidi/MIDIMessageEventInit.cpp',
       '<(blink_modules_output_dir)/webmidi/MIDIOptions.cpp',
       '<(blink_modules_output_dir)/webmidi/MIDIOptions.h',
       '<(blink_modules_output_dir)/websockets/CloseEventInit.cpp',
       '<(blink_modules_output_dir)/websockets/CloseEventInit.h',
+      '<(blink_modules_output_dir)/webusb/USBConnectionEventInit.cpp',
+      '<(blink_modules_output_dir)/webusb/USBConnectionEventInit.h',
       '<(blink_modules_output_dir)/webusb/USBDeviceFilter.cpp',
       '<(blink_modules_output_dir)/webusb/USBDeviceFilter.h',
       '<(blink_modules_output_dir)/webusb/USBDeviceRequestOptions.cpp',
       '<(blink_modules_output_dir)/webusb/USBDeviceRequestOptions.h',
     ],
     'modules_files': [
       '<@(extra_blink_module_files)',
       '<@(generated_modules_dictionary_files)',
       '<@(generated_modules_files)',
       'InitModules.cpp',
@@ skipping 1076 matching lines @@
       'websockets/WorkerWebSocketChannel.cpp',
       'websockets/WorkerWebSocketChannel.h',
       'webusb/NavigatorUSB.cpp',
       'webusb/NavigatorUSB.h',
       'webusb/USB.cpp',
       'webusb/USB.h',
       'webusb/USBAlternateInterface.cpp',
       'webusb/USBAlternateInterface.h',
       'webusb/USBConfiguration.cpp',
       'webusb/USBConfiguration.h',
+      'webusb/USBConnectionEvent.cpp',
+      'webusb/USBConnectionEvent.h',
       'webusb/USBController.cpp',
       'webusb/USBController.h',
       'webusb/USBDevice.cpp',
       'webusb/USBDevice.h',
       'webusb/USBEndpoint.cpp',
       'webusb/USBEndpoint.h',
       'webusb/USBError.cpp',
       'webusb/USBError.h',
       'webusb/USBInterface.cpp',
       'webusb/USBInterface.h',
@@ skipping 59 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }