Fix UB function problems for shaders and mask.

include/core/SkShader.h

Index: include/core/SkShader.h
diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index 34cb648022ca25593943ba054f7d196ad2c26bc2..e81bccfbf37186242db49460db38876c15fd42d1 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -149,7 +149,7 @@ public:
          */
         virtual void shadeSpan(int x, int y, SkPMColor[], int count) = 0;
 
-        typedef void (*ShadeProc)(void* ctx, int x, int y, SkPMColor[], int count);
+        typedef void (*ShadeProc)(const void* ctx, int x, int y, SkPMColor[], int count);

[reed1, 2015/12/17 18:12:14]

Its seems odd to me that this is declared const, since the logical equivalent is
to just call shadeSpan(), which is not const.

Can the caller in BitmapProc just not make its local variable const?

[herb_g, 2015/12/17 19:59:22]

Added comment as per our discussion.

         virtual ShadeProc asAShadeProc(void** ctx);
 
         /**