ServiceWorker, remove old Cache API implementation to make way for the polyfill.

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 97 matching lines @@
       'performance/WorkerPerformance.idl',
       'push_messaging/PushManager.idl',
       'push_messaging/PushRegistration.idl',
       'quota/DeprecatedStorageInfo.idl',
       'quota/DeprecatedStorageQuota.idl',
       'quota/StorageErrorCallback.idl',
       'quota/StorageInfo.idl',
       'quota/StorageQuota.idl',
       'quota/StorageQuotaCallback.idl',
       'quota/StorageUsageCallback.idl',
-      'serviceworkers/Cache.idl',
       'serviceworkers/Client.idl',
       'serviceworkers/FetchEvent.idl',
       'serviceworkers/HeaderMap.idl',
       'serviceworkers/HeaderMapForEachCallback.idl',
       'serviceworkers/InstallEvent.idl',
       'serviceworkers/InstallPhaseEvent.idl',
       'serviceworkers/Request.idl',
       'serviceworkers/Response.idl',
       'serviceworkers/ServiceWorker.idl',
       'serviceworkers/ServiceWorkerClients.idl',
@@ skipping 504 matching lines @@
       'quota/StorageQuotaClient.h',
       'quota/StorageUsageCallback.h',
       'quota/WorkerNavigatorStorageQuota.cpp',
       'quota/WorkerNavigatorStorageQuota.h',
       'screen_orientation/LockOrientationCallback.cpp',
       'screen_orientation/LockOrientationCallback.h',
       'screen_orientation/ScreenOrientation.cpp',
       'screen_orientation/ScreenOrientation.h',
       'screen_orientation/ScreenOrientationController.cpp',
       'screen_orientation/ScreenOrientationController.h',
-      'serviceworkers/Cache.cpp',
-      'serviceworkers/Cache.h',
       'serviceworkers/Client.cpp',
       'serviceworkers/Client.h',
       'serviceworkers/FetchEvent.cpp',
       'serviceworkers/FetchEvent.h',
       'serviceworkers/HeaderMap.cpp',
       'serviceworkers/HeaderMap.h',
       'serviceworkers/HeaderMapForEachCallback.h',
       'serviceworkers/InstallEvent.cpp',
       'serviceworkers/InstallEvent.h',
       'serviceworkers/InstallPhaseEvent.cpp',
@@ skipping 312 matching lines @@
       'indexeddb/IDBRequestTest.cpp',
       'indexeddb/IDBTransactionTest.cpp',
       'websockets/WebSocketDeflaterTest.cpp',
       'websockets/WebSocketExtensionDispatcherTest.cpp',
       'websockets/WebSocketExtensionParserTest.cpp',
       'websockets/WebSocketPerMessageDeflateTest.cpp',
       'websockets/WebSocketTest.cpp',
     ],
   },
 }