rename gradients private BitmapCache to GradientBitmapCache

R=caryclark@google.com
NOTREECHECKS=True

Author: reed@google.com

Review URL: https://codereview.chromium.org/474983005
diff --git a/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index cf6c671..7c9d9c3 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -8,6 +8,7 @@
 #ifndef SkGradientShaderPriv_DEFINED
 #define SkGradientShaderPriv_DEFINED
 
+#include "SkGradientBitmapCache.h"
 #include "SkGradientShader.h"
 #include "SkClampRange.h"
 #include "SkColorPriv.h"
@@ -16,7 +17,6 @@
 #include "SkMallocPixelRef.h"
 #include "SkUtils.h"
 #include "SkTemplates.h"
-#include "SkBitmapCache.h"
 #include "SkShader.h"
 #include "SkOnce.h"