Reverse style resolution to avoid N^2 walk when building the render tree

Source/core/core.gypi

 {
     'variables': {
         'core_idl_files': [
             'css/CSS.idl',
             'css/CSSCharsetRule.idl',
             'css/CSSFontFaceLoadEvent.idl',
             'css/CSSFontFaceRule.idl',
             'css/CSSHostRule.idl',
             'css/CSSImportRule.idl',
             'css/CSSKeyframeRule.idl',
@@ skipping 1979 matching lines @@
             'dom/UserActionElementSet.cpp',
             'dom/UserActionElementSet.h',
             'dom/UserGestureIndicator.cpp',
             'dom/UserTypingGestureIndicator.cpp',
             'dom/ViewportArguments.cpp',
             'dom/ViewportArguments.h',
             'dom/VisitedLinkState.cpp',
             'dom/VisitedLinkState.h',
             'dom/WheelController.cpp',
             'dom/WheelController.h',
+            'dom/WhitespaceChildList.h',
             'events/AutocompleteErrorEvent.h',
             'events/BeforeLoadEvent.h',
             'events/BeforeTextInsertedEvent.cpp',
             'events/BeforeTextInsertedEvent.h',
             'events/BeforeUnloadEvent.cpp',
             'events/BeforeUnloadEvent.h',
             'events/ClipboardEvent.cpp',
             'events/ClipboardEvent.h',
             'events/CompositionEvent.cpp',
             'events/CompositionEvent.h',
@@ skipping 1809 matching lines @@
                 'bison_exe': 'bison',
                 # We specify a preprocess so it happens locally and won't get
                 # distributed to goma.
                 # FIXME: /usr/bin/gcc won't exist on OSX forever. We want to
                 # use /usr/bin/clang once we require Xcode 4.x.
                 'preprocessor': '--preprocessor "/usr/bin/gcc -E -P -x c++"'
               }],
          ],
     }
 }