use colortype instead of config

clone of https://codereview.chromium.org/305133006/

TBR=

BUG=skia:

Author: reed@google.com

Review URL: https://codereview.chromium.org/301233011
diff --git a/src/utils/SkPictureUtils.cpp b/src/utils/SkPictureUtils.cpp
index 4dcb855..a2d6da1 100644
--- a/src/utils/SkPictureUtils.cpp
+++ b/src/utils/SkPictureUtils.cpp
@@ -114,7 +114,7 @@
     virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
                             const SkMatrix&, const SkPaint& paint) SK_OVERRIDE {
         this->addBitmap(bitmap);
-        if (SkBitmap::kA8_Config == bitmap.config()) {
+        if (kAlpha_8_SkColorType == bitmap.colorType()) {
             this->addBitmapFromPaint(paint);
         }
     }
@@ -123,7 +123,7 @@
                                 const SkPaint& paint,
                                 SkCanvas::DrawBitmapRectFlags flags) SK_OVERRIDE {
         this->addBitmap(bitmap);
-        if (SkBitmap::kA8_Config == bitmap.config()) {
+        if (kAlpha_8_SkColorType == bitmap.colorType()) {
             this->addBitmapFromPaint(paint);
         }
     }