Implement support for link type serviceworker in link elements.

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
@@ skipping 1459 matching lines @@
       'serviceworkers/ServiceWorker.cpp',
       'serviceworkers/ServiceWorker.h',
       'serviceworkers/ServiceWorkerClient.cpp',
       'serviceworkers/ServiceWorkerClient.h',
       'serviceworkers/ServiceWorkerClients.cpp',
       'serviceworkers/ServiceWorkerClients.h',
       'serviceworkers/ServiceWorkerContainer.cpp',
       'serviceworkers/ServiceWorkerContainer.h',
       'serviceworkers/ServiceWorkerContainerClient.cpp',
       'serviceworkers/ServiceWorkerContainerClient.h',
+      'serviceworkers/ServiceWorkerLinkResource.cpp',
+      'serviceworkers/ServiceWorkerLinkResource.h',
       'serviceworkers/ServiceWorkerWindowClient.cpp',
       'serviceworkers/ServiceWorkerWindowClient.h',
       'serviceworkers/ServiceWorkerWindowClientCallback.cpp',
       'serviceworkers/ServiceWorkerWindowClientCallback.h',
       'serviceworkers/ServiceWorkerError.cpp',
       'serviceworkers/ServiceWorkerError.h',
       'serviceworkers/ServiceWorkerGlobalScope.cpp',
       'serviceworkers/ServiceWorkerGlobalScope.h',
       'serviceworkers/ServiceWorkerGlobalScopeClient.cpp',
       'serviceworkers/ServiceWorkerGlobalScopeClient.h',
@@ skipping 499 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }