Merge tomhudson and mtklein SkPaint shrinking approaches.

src/core/SkPictureFlat.h

Index: src/core/SkPictureFlat.h
diff --git a/src/core/SkPictureFlat.h b/src/core/SkPictureFlat.h
index 7973e65398188d720fd06db7fedcb25512a3a438..48ae8495fddc42771da6d03bbcaa8d1698cdf281 100644
--- a/src/core/SkPictureFlat.h
+++ b/src/core/SkPictureFlat.h
@@ -561,15 +561,7 @@ private:
                    SkFlatData::Identity, SkFlatData::Hash, SkFlatData::Equal> fHash;
 };
 
-struct SkPaintTraits {
-    static void flatten(SkWriteBuffer& buffer, const SkPaint& paint) {
-        paint.flatten(buffer);
-    }
-    static void unflatten(SkReadBuffer& buffer, SkPaint* paint) {
-        paint->unflatten(buffer);
-    }
-};
-typedef SkFlatDictionary<SkPaint, SkPaintTraits> SkPaintDictionary;
+typedef SkFlatDictionary<SkPaint, SkPaint::FlatteningTraits> SkPaintDictionary;
 
 class SkChunkFlatController : public SkFlatController {
 public: