[WIP] Migrate Fullscreen to use top layer instead of RenderFullScreen

Source/core/core.gypi

 {
     'variables': {
         'core_idl_files': [
             'css/CSS.idl',
             'css/CSSCharsetRule.idl',
             'css/CSSFontFaceLoadEvent.idl',
             'css/CSSFontFaceRule.idl',
             'css/CSSHostRule.idl',
             'css/CSSImportRule.idl',
             'css/CSSMediaRule.idl',
@@ skipping 1318 matching lines @@
             'rendering/RenderFileUploadControl.cpp',
             'rendering/RenderFileUploadControl.h',
             'rendering/RenderFlexibleBox.cpp',
             'rendering/RenderFlexibleBox.h',
             'rendering/RenderFlowThread.cpp',
             'rendering/RenderFlowThread.h',
             'rendering/RenderFrame.cpp',
             'rendering/RenderFrame.h',
             'rendering/RenderFrameSet.cpp',
             'rendering/RenderFrameSet.h',
-            'rendering/RenderFullScreen.cpp',
-            'rendering/RenderFullScreen.h',
             'rendering/RenderGrid.cpp',
             'rendering/RenderGrid.h',
             'rendering/RenderGeometryMap.cpp',
             'rendering/RenderGeometryMap.h',
             'rendering/RenderHTMLCanvas.cpp',
             'rendering/RenderHTMLCanvas.h',
             'rendering/RenderIFrame.cpp',
             'rendering/RenderIFrame.h',
             'rendering/RenderImage.cpp',
             'rendering/RenderImageResource.cpp',
@@ skipping 2382 matching lines @@
                 'bison_exe': 'bison',
                 # We specify a preprocess so it happens locally and won't get
                 # distributed to goma.
                 # FIXME: /usr/bin/gcc won't exist on OSX forever. We want to
                 # use /usr/bin/clang once we require Xcode 4.x.
                 'preprocessor': '--preprocessor "/usr/bin/gcc -E -P -x c++"'
               }],
          ],
     }
 }