Move Web-facing fullscreen APIs to DocumentFullscreen and ElementFullscreen

Source/core/core.gypi

 {
     'includes': [
       'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/Animation.idl',
             'animation/AnimationEffect.idl',
             'animation/AnimationPlayer.idl',
@@ skipping 448 matching lines @@
             'xml/XSLTProcessor.idl',
         ],
         # 'partial interface', target (right side of) 'implements', and
         # interfaces with static bindings (in bindings/core/v8/)
         'core_dependency_idl_files': [
             'animation/DocumentAnimation.idl',
             'animation/ElementAnimation.idl',
             'css/DocumentFontFaceSet.idl',
             'dom/ChildNode.idl',
             'dom/DocumentFullscreen.idl',
+            'dom/ElementFullscreen.idl',
             'dom/GlobalEventHandlers.idl',
             'dom/ParentNode.idl',
             'dom/URLUtils.idl',
             'dom/URLUtilsReadOnly.idl',
             'events/EventListener.idl',
             'events/NavigatorEvents.idl',
             'frame/NavigatorCPU.idl',
             'frame/NavigatorID.idl',
             'frame/NavigatorLanguage.idl',
             'frame/NavigatorOnLine.idl',
@@ skipping 1531 matching lines @@
             'dom/DocumentStyleSheetCollection.h',
             'dom/DocumentStyleSheetCollector.cpp',
             'dom/DocumentStyleSheetCollector.h',
             'dom/DocumentType.cpp',
             'dom/Element.cpp',
             'dom/Element.h',
             'dom/ElementData.cpp',
             'dom/ElementData.h',
             'dom/ElementDataCache.cpp',
             'dom/ElementDataCache.h',
+            'dom/ElementFullscreen.cpp',
+            'dom/ElementFullscreen.h',
             'dom/ElementRareData.cpp',
             'dom/ElementRareData.h',
             'dom/ElementTraversal.h',
             'dom/EmptyNodeList.cpp',
             'dom/EmptyNodeList.h',
             'dom/ExecutionContext.cpp',
             'dom/ExecutionContext.h',
             'dom/ExecutionContextTask.h',
             'dom/FullscreenElementStack.cpp',
             'dom/FullscreenElementStack.h',
@@ skipping 1427 matching lines @@
             'rendering/shapes/BoxShapeTest.cpp',
             'rendering/style/OutlineValueTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'streams/ReadableStreamTest.cpp',
             'testing/UnitTestHelpers.cpp',
             'testing/UnitTestHelpers.h',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }