For *ToFixed, in debug mode, assert that the value is in range.

src/core/SkScan.h

Index: src/core/SkScan.h
diff --git a/src/core/SkScan.h b/src/core/SkScan.h
index 7309a1dd8c3ae3c67ebefa065ef072022d474427..2ae10f614bb65c8345cb96b9134434c1c372fa8b 100644
--- a/src/core/SkScan.h
+++ b/src/core/SkScan.h
@@ -93,7 +93,7 @@ static inline void XRect_set(SkXRect* xr, const SkIRect& src) {
 }
 
 /** Assign an SkXRect from a SkRect, by promoting the src rect's coordinates
-    from SkScalar to SkFixed. Does not check for overflow if the src coordinates
+    from SkScalar to SkFixed. Behavior is undefined if the src coordinates
     exceed 32K
 */
 static inline void XRect_set(SkXRect* xr, const SkRect& src) {