Experimental viewport meta tag support for desktop, Blink-side.

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 786 matching lines @@
             'css/StyleRule.cpp',
             'css/StyleRule.h',
             'css/StyleRuleImport.cpp',
             'css/StyleRuleImport.h',
             'css/StyleSheet.cpp',
             'css/StyleSheet.h',
             'css/StyleSheetContents.cpp',
             'css/StyleSheetContents.h',
             'css/StyleSheetList.cpp',
             'css/StyleSheetList.h',
+            'css/ViewportStyle.cpp',
+            'css/ViewportStyleAndroid.cpp',
+            'css/ViewportStyle.h',
             'css/resolver/AnimatedStyleBuilder.cpp',
             'css/resolver/AnimatedStyleBuilder.h',
             'css/resolver/ElementResolveContext.cpp',
             'css/resolver/ElementResolveContext.h',
             'css/resolver/ElementStyleResources.cpp',
             'css/resolver/ElementStyleResources.h',
             'css/resolver/FilterOperationResolver.cpp',
             'css/resolver/FilterOperationResolver.h',
             'css/resolver/FontBuilder.cpp',
             'css/resolver/FontBuilder.h',
@@ skipping 2730 matching lines @@
             'platform/graphics/gpu/DrawingBufferTest.cpp',
             'platform/image-decoders/ImageDecoderTest.cpp',
             'platform/image-decoders/gif/GIFImageDecoderTest.cpp',
             'platform/image-decoders/jpeg/JPEGImageDecoderTest.cpp',
             'platform/image-decoders/webp/WEBPImageDecoderTest.cpp',
             'platform/testing/FakeWebGraphicsContext3D.h',
             'rendering/RenderOverflowTest.cpp',
         ],
     }
 }