blink: Remove the use of WebWorkerRunLoop.

Source/web/web.gypi

 {
   'variables': {
     'web_files': [
       'AssertMatchingEnums.cpp',
       'AssociatedURLLoader.cpp',
       'AssociatedURLLoader.h',
       'ChromeClientImpl.cpp',
       'ChromeClientImpl.h',
       'ColorChooserPopupUIController.cpp',
       'ColorChooserPopupUIController.h',
@@ skipping 237 matching lines @@
       'WebTextCheckingCompletionImpl.h',
       'WebTextCheckingResult.cpp',
       'WebTextInputInfo.cpp',
       'WebTextRun.cpp',
       'WebThreadedDataReceiver.cpp',
       'WebUserGestureIndicator.cpp',
       'WebUserGestureToken.cpp',
       'WebUserMediaRequest.cpp',
       'WebViewImpl.cpp',
       'WebViewImpl.h',
-      'WebWorkerRunLoop.cpp',
       'WorkerGlobalScopeProxyProviderImpl.cpp',
       'WorkerGlobalScopeProxyProviderImpl.h',
       'WorkerPermissionClient.cpp',
       'WorkerPermissionClient.h',
       'default/WebRenderTheme.cpp',
       'linux/WebFontRendering.cpp',
       'mac/WebScrollbarTheme.mm',
       'mac/WebSubstringUtil.mm',
       'painting/ContinuousPainter.cpp',
       'painting/ContinuousPainter.h',
@@ skipping 85 matching lines @@
       ['os_posix==1 and OS!="mac"',
         {
           'web_unittest_files': [
             'tests/LocaleICUTest.cpp',
           ],
         }
       ],
     ],
   },
 }