Revert of Remove SK_SUPPORT_LEGACY_DEEPFLATTENING.

include/effects/SkComposeImageFilter.h

Index: include/effects/SkComposeImageFilter.h
diff --git a/include/effects/SkComposeImageFilter.h b/include/effects/SkComposeImageFilter.h
index 0478909cd19053d2c3551796435c3dad9a95835b..26eed378722d2d2d728674658108bcf3c9907680 100644
--- a/include/effects/SkComposeImageFilter.h
+++ b/include/effects/SkComposeImageFilter.h
@@ -32,6 +32,10 @@
         SkASSERT(inputs[0]);
         SkASSERT(inputs[1]);
     }
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+    explicit SkComposeImageFilter(SkReadBuffer& buffer);
+#endif
+
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                                SkBitmap* result, SkIPoint* loc) const SK_OVERRIDE;
     virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) const SK_OVERRIDE;