Implement InterpolationMedium to filter animated images

Source/platform/graphics/skia/NativeImageSkia.h

Index: Source/platform/graphics/skia/NativeImageSkia.h
diff --git a/Source/platform/graphics/skia/NativeImageSkia.h b/Source/platform/graphics/skia/NativeImageSkia.h
index 97b7bcd76bddbcb088995e27fe93e28d6c4e582e..7ce583b37501e86eb1c9ad87c4f57f5cb24dd404 100644
--- a/Source/platform/graphics/skia/NativeImageSkia.h
+++ b/Source/platform/graphics/skia/NativeImageSkia.h
@@ -62,6 +62,9 @@ enum ResamplingMode {
     // quality resampling doesn't get us very much except a slowdown.
     LinearResampling,
 
+    // LinearResampling for upscaling. Mipmapping for downscaling.
+    MediumResampling,

[Stephen White, 2014/03/18 17:26:43]

Bikeshed: maybe this should be LinearMipmaps or LinearWithMipmaps or something.
The other types in this enum refer to algorithms, while this seems to belong
more to high/medium/low.

[Alpha Left Google, 2014/03/18 22:59:13]

Done.

+
     // High quality resampling.
     AwesomeResampling,
 };