Disable mask-filtered mask caching in Skia

Chrome-side companion to the Skia CL:

https://skia-review.googlesource.com/c/skia/+/150080 (Add a flag to disable mask-filtered mask caching for Chrome)

Bug: 878195
Change-Id: I8f2f7f2c5fb6dc5a9091750361722bd022e38a45
Reviewed-on: https://chromium-review.googlesource.com/1193968
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
Cr-Commit-Position: refs/heads/master@{#586745}

skia/config/SkUserConfig.h

@@ -173,6 +173,10 @@ SK_API void SkDebugf_FileLine(const char* file, int line, bool fatal,
 #define SK_IGNORE_MATRIX_IMAGE_FILTER_FIX
 #endif
 
+#ifndef SK_DISABLE_MASKFILTERED_MASK_CACHING
+#define SK_DISABLE_MASKFILTERED_MASK_CACHING
+#endif
+
 // remove after rebaselining svg layout tests
 #ifndef SK_SUPPORT_LEGACY_SVG_ARC_TO
 #define SK_SUPPORT_LEGACY_SVG_ARC_TO