Revert "Revert "SkTypes: extract SkTo""

This reverts commit fdcfb8b7c23fbf18f872d2c31d27978235033876.

> Original change's description:
> > SkTypes: extract SkTo
> >
> > Change-Id: I8de790d5013db2105ad885fa2683303d7c250b09
> > Reviewed-on: https://skia-review.googlesource.com/133620
> > Reviewed-by: Mike Klein <mtklein@google.com>

Change-Id: Ida74fbc5c21248a724a5edbf9fae18a33bcb23aa
Reviewed-on: https://skia-review.googlesource.com/134506
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
diff --git a/src/core/SkAAClip.cpp b/src/core/SkAAClip.cpp
index fc8f771..46c09e0 100644
--- a/src/core/SkAAClip.cpp
+++ b/src/core/SkAAClip.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SkAAClip.h"
+
 #include "SkAtomics.h"
 #include "SkBlitter.h"
 #include "SkColorData.h"
@@ -13,6 +14,7 @@
 #include "SkPath.h"
 #include "SkRectPriv.h"
 #include "SkScan.h"
+#include "SkTo.h"
 #include "SkUtils.h"
 
 class AutoAAClipValidate {