lock pixels in image when bitmap is immutable and not-lazy

include/core/SkPixelRef.h

Index: include/core/SkPixelRef.h
diff --git a/include/core/SkPixelRef.h b/include/core/SkPixelRef.h
index a67855de5fbf03fa8872f9f02dd6ac75e1b3007c..1dc01f79abb1f650dd0688bb84367d2c3f4d38fa 100644
--- a/include/core/SkPixelRef.h
+++ b/include/core/SkPixelRef.h
@@ -19,20 +19,6 @@
 #include "SkString.h"
 #include "SkTDArray.h"
 
-#ifdef SK_DEBUG
-    /**
-     *  Defining SK_IGNORE_PIXELREF_SETPRELOCKED will force all pixelref
-     *  subclasses to correctly handle lock/unlock pixels. For performance
-     *  reasons, simple malloc-based subclasses call setPreLocked() to skip
-     *  the overhead of implementing these calls.
-     *
-     *  This build-flag disables that optimization, to add in debugging our
-     *  call-sites, to ensure that they correctly balance their calls of
-     *  lock and unlock.
-     */
-//    #define SK_IGNORE_PIXELREF_SETPRELOCKED
-#endif
-
 class SkColorTable;
 class SkData;
 struct SkIRect;
@@ -385,6 +371,9 @@ private:
     void restoreMutability();
     friend class SkSurface_Raster;   // For the two methods above.
 
+    bool isPreLocked() const { return fPreLocked; }
+    friend class SkImage_Raster;
+
     // When copying a bitmap to another with the same shape and config, we can safely
     // clone the pixelref generation ID too, which makes them equivalent under caching.
     friend class SkBitmap;  // only for cloneGenID