Track connected subframes per-Document instead of per-Node.

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 2291 matching lines @@
             'dom/AXObjectCache.h',
             'dom/ActiveDOMObject.cpp',
             'dom/AddConsoleMessageTask.cpp',
             'dom/AddConsoleMessageTask.h',
             'dom/Attr.cpp',
             'dom/AttributeCollection.h',
             'dom/CDATASection.cpp',
             'dom/CDATASection.h',
             'dom/CSSSelectorWatch.cpp',
             'dom/CharacterData.cpp',
-            'dom/ChildFrameDisconnector.cpp',
-            'dom/ChildFrameDisconnector.h',
             'dom/ChildListMutationScope.cpp',
             'dom/ChildListMutationScope.h',
             'dom/ChildNodeList.cpp',
             'dom/ChildNodeList.h',
             'dom/ClassCollection.cpp',
             'dom/ClassCollection.h',
             'dom/ClientRect.cpp',
             'dom/ClientRect.h',
             'dom/ClientRectList.cpp',
             'dom/ClientRectList.h',
@@ skipping 221 matching lines @@
             'dom/StyleChangeReason.cpp',
             'dom/StyleChangeReason.h',
             'dom/StyleElement.cpp',
             'dom/StyleElement.h',
             'dom/StyleEngine.cpp',
             'dom/StyleEngine.h',
             'dom/StyleSheetCandidate.cpp',
             'dom/StyleSheetCandidate.h',
             'dom/StyleSheetCollection.cpp',
             'dom/StyleSheetCollection.h',
+            'dom/SubframeTracker.cpp',
+            'dom/SubframeTracker.h',
             'dom/Suborigin.cpp',
             'dom/Suborigin.h',
             'dom/TagCollection.cpp',
             'dom/TagCollection.h',
             'dom/Text.cpp',
             'dom/TextLinkColors.cpp',
             'dom/TextLinkColors.h',
             'dom/Touch.cpp',
             'dom/Touch.h',
             'dom/TouchList.cpp',
@@ skipping 1489 matching lines @@
             'style/SVGComputedStyleTest.cpp',
             'svg/SVGPathParserTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }