Remove unused NeedsDeepCopy.

src/core/SkPaintPriv.cpp

Index: src/core/SkPaintPriv.cpp
diff --git a/src/core/SkPaintPriv.cpp b/src/core/SkPaintPriv.cpp
index d7b3032227dd94698236876dfb43e767ca3566d6..ce0538901922fde98f8e6e9695a7cdd1fab5caee 100644
--- a/src/core/SkPaintPriv.cpp
+++ b/src/core/SkPaintPriv.cpp
@@ -76,14 +76,3 @@ bool isPaintOpaque(const SkPaint* paint,
     }
     return false;
 }
-
-bool NeedsDeepCopy(const SkPaint& paint) {
-    /*
-     *  The types below are not yet immutable/reentrant-safe, and so we return
-     *  true if instances of them are present in the paint.
-     *
-     *  Eventually we hope this list will be empty, and we can always return
-     *  false.
-     */
-    return paint.getImageFilter();
-}