Add EventHandlerRegistry

Source/core/core.gypi

 {
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/Animation.idl',
             'animation/AnimationPlayer.idl',
             'animation/TimedItem.idl',
             'animation/Timeline.idl',
             'animation/Timing.idl',
             'clipboard/DataTransfer.idl',
@@ skipping 2018 matching lines @@
             'dom/SandboxFlags.h',
             'dom/SandboxFlags.cpp',
             'dom/ScriptableDocumentParser.cpp',
             'dom/ScriptableDocumentParser.h',
             'dom/ScriptedAnimationController.cpp',
             'dom/ScriptedAnimationController.h',
             'dom/ExecutionContext.cpp',
             'dom/ScriptLoader.cpp',
             'dom/ScriptLoader.h',
             'dom/ScriptRunner.cpp',
+            'dom/ScrollEventHandlerController.cpp',
+            'dom/ScrollEventHandlerController.h',
             'dom/SecurityContext.cpp',
             'dom/SecurityContext.h',
             'dom/SelectorQuery.cpp',
             'dom/SelectorQuery.h',
             'dom/XMLDocument.cpp',
             'dom/XMLDocument.h',
             'dom/custom/CustomElement.cpp',
             'dom/custom/CustomElement.h',
             'dom/custom/CustomElementCallbackDispatcher.cpp',
             'dom/custom/CustomElementCallbackDispatcher.h',
@@ skipping 1274 matching lines @@
             'html/track/vtt/BufferedLineReaderTest.cpp',
             'html/track/vtt/VTTScannerTest.cpp',
             'rendering/RenderOverflowTest.cpp',
             'rendering/shapes/BoxShapeTest.cpp',
             'testing/UnitTestHelpers.cpp',
             'testing/UnitTestHelpers.h',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }