Remove unused NeedsDeepCopy.

It was used to check to see if an SkPaint had mutable fields on it.
Now that all the fields are immutable, this function is no longer
used. Remove it.

BUG=skia:2097

Review URL: https://codereview.chromium.org/661543002

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();
-}

src/core/SkPaintPriv.h

@@ -22,11 +22,4 @@ class SkPaint;
 */
 bool isPaintOpaque(const SkPaint* paint,
                    const SkBitmap* bmpReplacesShader = NULL);
-
-/** Returns true if the provided paint has fields which are not
-    immutable (and will thus require deep copying).
-    @param paint the paint to be analyzed
-    @return true if the paint requires a deep copy
-*/
-bool NeedsDeepCopy(const SkPaint& paint);
 #endif