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/utils/SkInterpolator.cpp b/src/utils/SkInterpolator.cpp
index d64316d..141adaf 100644
--- a/src/utils/SkInterpolator.cpp
+++ b/src/utils/SkInterpolator.cpp
@@ -8,9 +8,10 @@
 #include "SkInterpolator.h"
 
 #include "SkFixed.h"
-#include "SkMath.h"
 #include "SkMalloc.h"
+#include "SkMath.h"
 #include "SkTSearch.h"
+#include "SkTo.h"
 
 SkInterpolatorBase::SkInterpolatorBase() {
     fStorage    = nullptr;
diff --git a/src/utils/SkLua.cpp b/src/utils/SkLua.cpp
index 53e8bb3..887e251 100644
--- a/src/utils/SkLua.cpp
+++ b/src/utils/SkLua.cpp
@@ -30,6 +30,7 @@
 #include "SkString.h"
 #include "SkSurface.h"
 #include "SkTextBlob.h"
+#include "SkTo.h"
 #include "SkTypeface.h"
 #include <new>
 
diff --git a/src/utils/SkLuaCanvas.cpp b/src/utils/SkLuaCanvas.cpp
index 53e462a..c7e3064 100644
--- a/src/utils/SkLuaCanvas.cpp
+++ b/src/utils/SkLuaCanvas.cpp
@@ -9,6 +9,7 @@
 
 #include "SkLua.h"
 #include "SkStringUtils.h"
+#include "SkTo.h"
 
 extern "C" {
     #include "lua.h"
diff --git a/src/utils/SkMultiPictureDocument.cpp b/src/utils/SkMultiPictureDocument.cpp
index 493e6d4..f7081e6 100644
--- a/src/utils/SkMultiPictureDocument.cpp
+++ b/src/utils/SkMultiPictureDocument.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SkMultiPictureDocument.h"
+
 #include "SkMultiPictureDocumentPriv.h"
 #include "SkNWayCanvas.h"
 #include "SkPicture.h"
@@ -13,6 +14,7 @@
 #include "SkSerialProcs.h"
 #include "SkStream.h"
 #include "SkTArray.h"
+#include "SkTo.h"
 
 #include <limits.h>
 
diff --git a/src/utils/SkPatchUtils.cpp b/src/utils/SkPatchUtils.cpp
index 8fafd14..a28abdf 100644
--- a/src/utils/SkPatchUtils.cpp
+++ b/src/utils/SkPatchUtils.cpp
@@ -10,6 +10,7 @@
 #include "SkColorData.h"
 #include "SkGeometry.h"
 #include "SkPM4f.h"
+#include "SkTo.h"
 
 namespace {
     enum CubicCtrlPts {
diff --git a/src/utils/mac/SkCreateCGImageRef.cpp b/src/utils/mac/SkCreateCGImageRef.cpp
index e7a78b0..300e23b 100644
--- a/src/utils/mac/SkCreateCGImageRef.cpp
+++ b/src/utils/mac/SkCreateCGImageRef.cpp
@@ -12,6 +12,7 @@
 #include "SkCGUtils.h"
 #include "SkColorData.h"
 #include "SkMacros.h"
+#include "SkTo.h"
 
 static CGBitmapInfo ComputeCGAlphaInfo_RGBA(SkAlphaType at) {
     CGBitmapInfo info = kCGBitmapByteOrder32Big;