stop using SkBitmap::Config

R=scroggo@google.com

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/338493005
diff --git a/src/images/SkImageDecoder_libgif.cpp b/src/images/SkImageDecoder_libgif.cpp
index 7b6a474..0c8461f 100644
--- a/src/images/SkImageDecoder_libgif.cpp
+++ b/src/images/SkImageDecoder_libgif.cpp
@@ -192,7 +192,7 @@
  *  fixes it.  This makes the output image consistantly deterministic.
  */
 static void sanitize_indexed_bitmap(SkBitmap* bm) {
-    if ((SkBitmap::kIndex8_Config == bm->config()) && !(bm->empty())) {
+    if ((kIndex_8_SkColorType == bm->colorType()) && !(bm->empty())) {
         SkAutoLockPixels alp(*bm);
         if (NULL != bm->getPixels()) {
             SkColorTable* ct = bm->getColorTable();  // Index8 must have it.