hide SkDevice::config()

TBR=robertphilips

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/302253002
diff --git a/src/utils/SkPictureUtils.cpp b/src/utils/SkPictureUtils.cpp
index 512b228..4dcb855 100644
--- a/src/utils/SkPictureUtils.cpp
+++ b/src/utils/SkPictureUtils.cpp
@@ -61,9 +61,11 @@
     virtual int width() const SK_OVERRIDE { return fSize.width(); }
     virtual int height() const SK_OVERRIDE { return fSize.height(); }
     virtual bool isOpaque() const SK_OVERRIDE { return false; }
+#ifdef SK_SUPPORT_LEGACY_DEVICE_CONFIG
     virtual SkBitmap::Config config() const SK_OVERRIDE {
         return SkBitmap::kNo_Config;
     }
+#endif
     virtual GrRenderTarget* accessRenderTarget() SK_OVERRIDE { return NULL; }
     virtual bool filterTextFlags(const SkPaint& paint, TextFlags*) SK_OVERRIDE {
         return false;