Start to implement FetchEvent for ServiceWorker

Source/modules/modules.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
@@ skipping 88 matching lines @@
       'notifications/NotificationPermissionCallback.idl',
       'notifications/WebKitNotification.idl',
       'performance/WorkerPerformance.idl',
       'quota/DeprecatedStorageInfo.idl',
       'quota/DeprecatedStorageQuota.idl',
       'quota/StorageErrorCallback.idl',
       'quota/StorageInfo.idl',
       'quota/StorageQuota.idl',
       'quota/StorageQuotaCallback.idl',
       'quota/StorageUsageCallback.idl',
+      'serviceworkers/FetchEvent.idl',
       'serviceworkers/InstallEvent.idl',
       'serviceworkers/InstallPhaseEvent.idl',
+      'serviceworkers/Response.idl',
       'serviceworkers/ServiceWorker.idl',
       'serviceworkers/ServiceWorkerContainer.idl',
       'serviceworkers/ServiceWorkerGlobalScope.idl',
       'speech/SpeechGrammar.idl',
       'speech/SpeechGrammarList.idl',
       'speech/SpeechRecognition.idl',
       'speech/SpeechRecognitionAlternative.idl',
       'speech/SpeechRecognitionError.idl',
       'speech/SpeechRecognitionEvent.idl',
       'speech/SpeechRecognitionResult.idl',
@@ skipping 413 matching lines @@
       'quota/StorageQuotaClient.h',
       'quota/StorageUsageCallback.h',
       'quota/WorkerNavigatorStorageQuota.cpp',
       'quota/WorkerNavigatorStorageQuota.h',
       'screen_orientation/ScreenOrientation.cpp',
       'screen_orientation/ScreenOrientation.h',
       'screen_orientation/ScreenOrientationController.cpp',
       'screen_orientation/ScreenOrientationController.h',
       'screen_orientation/ScreenOrientationDispatcher.cpp',
       'screen_orientation/ScreenOrientationDispatcher.h',
+      'serviceworkers/FetchEvent.cpp',
+      'serviceworkers/FetchEvent.h',
       'serviceworkers/InstallEvent.cpp',
       'serviceworkers/InstallEvent.h',
       'serviceworkers/InstallPhaseEvent.cpp',
       'serviceworkers/InstallPhaseEvent.h',
       'serviceworkers/NavigatorServiceWorker.cpp',
       'serviceworkers/NavigatorServiceWorker.h',
       'serviceworkers/RegistrationOptionList.h',
+      'serviceworkers/RespondWithObserver.cpp',
+      'serviceworkers/RespondWithObserver.h',
+      'serviceworkers/Response.cpp',
+      'serviceworkers/Response.h',
       'serviceworkers/ServiceWorker.cpp',
       'serviceworkers/ServiceWorker.h',
       'serviceworkers/ServiceWorkerContainer.cpp',
       'serviceworkers/ServiceWorkerContainer.h',
       'serviceworkers/ServiceWorkerContainerClient.cpp',
       'serviceworkers/ServiceWorkerContainerClient.h',
       'serviceworkers/ServiceWorkerError.cpp',
       'serviceworkers/ServiceWorkerError.h',
       'serviceworkers/ServiceWorkerGlobalScope.cpp',
       'serviceworkers/ServiceWorkerGlobalScope.h',
@@ skipping 283 matching lines @@
       'indexeddb/IDBKeyPathTest.cpp',
       'indexeddb/IDBRequestTest.cpp',
       'indexeddb/IDBTransactionTest.cpp',
       'websockets/WebSocketDeflaterTest.cpp',
       'websockets/WebSocketExtensionDispatcherTest.cpp',
       'websockets/WebSocketExtensionParserTest.cpp',
       'websockets/WebSocketPerMessageDeflateTest.cpp',
     ],
   },
 }