hide discardable factory from public imagegenerator api

BUG=skia:
R=halcanary@google.com, scroggo@google.com, djsollen@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/295243006

git-svn-id: http://skia.googlecode.com/svn/trunk@14889 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/DrawBitmapRectTest.cpp b/tests/DrawBitmapRectTest.cpp
index e6cc781..f294ae7 100644
--- a/tests/DrawBitmapRectTest.cpp
+++ b/tests/DrawBitmapRectTest.cpp
@@ -9,7 +9,7 @@
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkDiscardableMemoryPool.h"
-#include "SkImageGenerator.h"
+#include "SkImageGeneratorPriv.h"
 #include "SkMatrixUtils.h"
 #include "SkPaint.h"
 #include "SkRandom.h"