Start to implement FetchEvent for ServiceWorker

Source/modules/modules.gypi

Index: Source/modules/modules.gypi
diff --git a/Source/modules/modules.gypi b/Source/modules/modules.gypi
index fd47121400fc1d24717ca858afea6b38ec0c9f9d..dd6678e3f194f480e569879b82c6a6d2ac865099 100644
--- a/Source/modules/modules.gypi
+++ b/Source/modules/modules.gypi
@@ -111,8 +111,10 @@
       'quota/StorageQuotaCallback.idl',
       'quota/StorageUsageCallback.idl',
       'serviceworkers/Cache.idl',
+      'serviceworkers/FetchEvent.idl',
       'serviceworkers/InstallEvent.idl',
       'serviceworkers/InstallPhaseEvent.idl',
+      'serviceworkers/Response.idl',
       'serviceworkers/ServiceWorker.idl',
       'serviceworkers/ServiceWorkerContainer.idl',
       'serviceworkers/ServiceWorkerGlobalScope.idl',
@@ -556,6 +558,8 @@
       'screen_orientation/ScreenOrientationDispatcher.h',
       'serviceworkers/Cache.cpp',
       'serviceworkers/Cache.h',
+      'serviceworkers/FetchEvent.cpp',
+      'serviceworkers/FetchEvent.h',
       'serviceworkers/InstallEvent.cpp',
       'serviceworkers/InstallEvent.h',
       'serviceworkers/InstallPhaseEvent.cpp',
@@ -563,6 +567,11 @@
       'serviceworkers/NavigatorServiceWorker.cpp',
       'serviceworkers/NavigatorServiceWorker.h',
       'serviceworkers/RegistrationOptionList.h',
+      'serviceworkers/RespondWithObserver.cpp',
+      'serviceworkers/RespondWithObserver.h',
+      'serviceworkers/Response.cpp',
+      'serviceworkers/Response.h',
+      'serviceworkers/ResponseInit.h',
       'serviceworkers/ServiceWorker.cpp',
       'serviceworkers/ServiceWorker.h',
       'serviceworkers/ServiceWorkerContainer.cpp',