Revert "SkTypes: extract SkTo"

This reverts commit 2a2f67592602b18527bc3fd449132d420cd5b62e.

Reason for revert: this appears to be what is holding up the Chrome roll.

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>

TBR=mtklein@google.com,halcanary@google.com

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: Iafd738aedfb679a23c061a51afe4b98a8d4cdfae
Reviewed-on: https://skia-review.googlesource.com/134504
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
diff --git a/src/core/SkVertices.cpp b/src/core/SkVertices.cpp
index 4aa56c8..e23d65f 100644
--- a/src/core/SkVertices.cpp
+++ b/src/core/SkVertices.cpp
@@ -5,14 +5,12 @@
  * found in the LICENSE file.
  */
 
-#include "SkVertices.h"
-
 #include "SkAtomics.h"
+#include "SkVertices.h"
 #include "SkData.h"
 #include "SkReader32.h"
 #include "SkSafeMath.h"
 #include "SkSafeRange.h"
-#include "SkTo.h"
 #include "SkWriter32.h"
 #include <new>