Sync core/timing/ interfaces with their specs, or lack thereof

Source/core/core.gypi

 {
     'includes': [
         'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/KeyframeEffect.idl',
             'animation/EffectModel.idl',
             'animation/AnimationEffectReadOnly.idl',
@@ skipping 479 matching lines @@
             'events/UIEvent.idl',
             'events/WheelEvent.idl',
             'html/MediaKeyEvent.idl',
             'html/track/TrackEvent.idl',
             'svg/SVGZoomEvent.idl',
             'xmlhttprequest/XMLHttpRequestProgressEvent.idl',
         ],
         # IDL files that only have typedefs/enums.
         'core_typedefs_enums_only_idl_files': [
             'dom/CommonDefinitions.idl',
+            'timing/DOMHighResTimeStamp.idl',
+            'timing/PerformanceEntryList.idl',
         ],
         'webcore_rendering_files': [
             'layout/api/LineLayoutBlockFlow.h',
             'layout/api/LineLayoutBox.h',
             'layout/api/LineLayoutInline.h',
             'layout/api/LineLayoutItem.h',
             'layout/api/LineLayoutText.h',
             'layout/BidiRun.h',
             'layout/BidiRunForLine.cpp',
             'layout/BidiRunForLine.h',
@@ skipping 3286 matching lines @@
             'style/OutlineValueTest.cpp',
             'style/SVGComputedStyleTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }