stop using deprecated bitmap::config for gpu

BUG=skia:
R=bsalomon@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/248473006

git-svn-id: http://skia.googlecode.com/svn/trunk@14330 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 46e0c95..f4bde67 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1109,7 +1109,7 @@
         desc.fHeight = 32;
         desc.fRowHeight = bitmap.height();
         desc.fContext = ctx;
-        desc.fConfig = SkImageInfo2GrPixelConfig(bitmap.colorType(), bitmap.alphaType());
+        desc.fConfig = SkImageInfo2GrPixelConfig(bitmap.info());
         fAtlas = GrTextureStripAtlas::GetAtlas(desc);
         SkASSERT(NULL != fAtlas);