Move Region.cpp/.h to platform/

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/CSSKeyframeRule.idl',
@@ skipping 3031 matching lines @@
             'platform/network/ResourceRequest.cpp',
             'platform/network/ResourceRequest.h',
             'platform/network/ResourceResponse.cpp',
             'platform/network/ResourceResponse.h',
             'platform/text/RegularExpression.cpp',
             'platform/text/transcoder/FontTranscoder.cpp',
             'platform/text/transcoder/FontTranscoder.h',
         ],
         'webcore_platform_geometry_files': [
             'platform/graphics/FloatPolygon.cpp',
-            'platform/graphics/Region.cpp',
         ],
         'webcore_svg_files': [
             'rendering/style/SVGRenderStyle.cpp',
             'rendering/style/SVGRenderStyleDefs.cpp',
             'rendering/svg/ReferenceFilterBuilder.cpp',
             'rendering/svg/ReferenceFilterBuilder.h',
             'rendering/svg/RenderSVGBlock.cpp',
             'rendering/svg/RenderSVGBlock.h',
             'rendering/svg/RenderSVGContainer.cpp',
             'rendering/svg/RenderSVGContainer.h',
@@ skipping 601 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++"'
               }],
          ],
     }
 }