Switch webkit_unit_tests to use the new test launcher.

Source/web/web.gypi

 {
   'variables': {
     'web_files': [
       'AssertMatchingEnums.cpp',
       'AssociatedURLLoader.cpp',
       'AssociatedURLLoader.h',
       'BackForwardClientImpl.cpp',
       'BackForwardClientImpl.h',
       'ChromeClientImpl.cpp',
       'ChromeClientImpl.h',
@@ skipping 295 matching lines @@
       'tests/WebInputEventFactoryTestMac.mm',
       'tests/WebPageNewSerializerTest.cpp',
       'tests/WebPageSerializerTest.cpp',
       'tests/WebPluginContainerTest.cpp',
       'tests/WebScopedWindowFocusAllowedIndicatorTest.cpp',
       'tests/WebSearchableFormDataTest.cpp',
       'tests/WebSelectorTest.cpp',
       'tests/WebURLRequestTest.cpp',
       'tests/WebURLResponseTest.cpp',
       'tests/WebUserGestureTokenTest.cpp',
+      'tests/WebUnitTests.cpp',
       'tests/WebViewTest.cpp',
     ],
     'conditions': [
       ['OS=="win"',
         {
           'web_unittest_files': [
             'tests/LocaleWinTest.cpp',
             'tests/WebPageNewSerializerTest.cpp',
             'tests/WebPageSerializerTest.cpp',
           ],
@@ skipping 17 matching lines @@
       ['os_posix==1 and OS!="mac"',
         {
           'web_unittest_files': [
             'tests/LocaleICUTest.cpp',
           ],
         }
       ],
     ],
   },
 }