Add feature extraction for distillability to Blink

third_party/WebKit/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 2298 matching lines @@
             'dom/DocumentInit.h',
             'dom/DocumentLifecycle.cpp',
             'dom/DocumentLifecycle.h',
             'dom/DocumentLifecycleNotifier.cpp',
             'dom/DocumentLifecycleNotifier.h',
             'dom/DocumentLifecycleObserver.h',
             'dom/DocumentOrderedList.cpp',
             'dom/DocumentOrderedList.h',
             'dom/DocumentOrderedMap.cpp',
             'dom/DocumentParser.cpp',
+            'dom/DocumentStatisticsCollector.cpp',
+            'dom/DocumentStatisticsCollector.h',
             'dom/DocumentStyleSheetCollection.cpp',
             'dom/DocumentStyleSheetCollection.h',
             'dom/DocumentStyleSheetCollector.cpp',
             'dom/DocumentStyleSheetCollector.h',
             'dom/DocumentTiming.cpp',
             'dom/DocumentTiming.h',
             'dom/DocumentType.cpp',
             'dom/DocumentVisibilityObserver.cpp',
             'dom/Element.cpp',
             'dom/Element.h',
@@ skipping 1578 matching lines @@
             'style/OutlineValueTest.cpp',
             'style/SVGComputedStyleTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }