Implement FullScreen using top layer.

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 557 matching lines @@
             'layout/LayoutFieldset.cpp',
             'layout/LayoutFieldset.h',
             'layout/LayoutFileUploadControl.cpp',
             'layout/LayoutFileUploadControl.h',
             'layout/LayoutFlowThread.cpp',
             'layout/LayoutFlowThread.h',
             'layout/LayoutFrame.cpp',
             'layout/LayoutFrame.h',
             'layout/LayoutFrameSet.cpp',
             'layout/LayoutFrameSet.h',
-            'layout/LayoutFullScreen.cpp',
-            'layout/LayoutFullScreen.h',
             'layout/LayoutGeometryMap.cpp',
             'layout/LayoutGeometryMap.h',
             'layout/LayoutGeometryMapStep.h',
             'layout/LayoutGrid.cpp',
             'layout/LayoutGrid.h',
             'layout/LayoutHTMLCanvas.cpp',
             'layout/LayoutHTMLCanvas.h',
             'layout/LayoutIFrame.cpp',
             'layout/LayoutIFrame.h',
             'layout/LayoutImage.cpp',
@@ skipping 3295 matching lines @@
             'style/OutlineValueTest.cpp',
             'style/SVGComputedStyleTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }