Import Dart bindings as of Blink r188698. This merely copies the files over and does not attach any…

sky/engine/bindings-dart/core/dart/shared_lib/DartNativeExtensions.h

Index: sky/engine/bindings-dart/core/dart/shared_lib/DartNativeExtensions.h
diff --git a/sky/engine/platform/fonts/FontPlatformFeatures.h b/sky/engine/bindings-dart/core/dart/shared_lib/DartNativeExtensions.h
similarity index 76%
copy from sky/engine/platform/fonts/FontPlatformFeatures.h
copy to sky/engine/bindings-dart/core/dart/shared_lib/DartNativeExtensions.h
index 0585176ce1b520f704e61a939c532dd271f644fb..cecba7d525d0601bb5947612b38c13923772fb98 100644
--- a/sky/engine/platform/fonts/FontPlatformFeatures.h
+++ b/sky/engine/bindings-dart/core/dart/shared_lib/DartNativeExtensions.h
@@ -28,21 +28,24 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef SKY_ENGINE_PLATFORM_FONTS_FONTPLATFORMFEATURES_H_
-#define SKY_ENGINE_PLATFORM_FONTS_FONTPLATFORMFEATURES_H_
+#ifndef DartNativeExtensions_h
+#define DartNativeExtensions_h
+
+#include "wtf/text/WTFString.h"
+#include <dart_api.h>
 
-#include "sky/engine/platform/PlatformExport.h"
 
 namespace blink {
 
-class FontPlatformFeatures {
+class DartNativeExtensions {
 public:
-    static bool canExpandAroundIdeographsInComplexText();
+    static Dart_Handle loadExtension(const String& url, Dart_Handle parentLibrary);
 
 private:
-    FontPlatformFeatures();
+    static Dart_Handle loadExtensionLibrary(const String& libraryPath, const String& libraryName, void** libraryHandle);
+    static Dart_Handle resolveSymbol(void* libHandle, const String& symbolName, void** symbol);
 };
 
-} // namespace blink
+}
 
-#endif  // SKY_ENGINE_PLATFORM_FONTS_FONTPLATFORMFEATURES_H_
+#endif // DartNativeExtensions_h