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/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 5a5489e..65280bc 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -5,6 +5,9 @@
 * found in the LICENSE file.
 */
 
+#include "Viewer.h"
+#include <stdlib.h>
+#include <map>
 #include "BisectSlide.h"
 #include "GMSlide.h"
 #include "GrContext.h"
@@ -34,15 +37,10 @@
 #include "SkTaskGroup.h"
 #include "SkTestFontMgr.h"
 #include "SkThreadedBMPDevice.h"
-#include "SkTo.h"
 #include "SvgSlide.h"
-#include "Viewer.h"
 #include "ccpr/GrCoverageCountingPathRenderer.h"
 #include "imgui.h"
 
-#include <stdlib.h>
-#include <map>
-
 #if defined(SK_HAS_SKSG)
     #include "SlideDir.h"
 #endif