Stop using SkTSwap.

Use std::swap instead. It does not appear that any external user
specializes SkTSwap, but some may still use it. This removes all use in
Skia so that SkTSwap can later be removed in a smaller CL. After that
the <utility> include can be removed from SkTypes.h.

Change-Id: If03d4ee07dbecda961aa9f0dc34d171ef5168753
Reviewed-on: https://skia-review.googlesource.com/135578
Reviewed-by: Hal Canary <halcanary@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/src/shaders/gradients/SkTwoPointConicalGradient.cpp b/src/shaders/gradients/SkTwoPointConicalGradient.cpp
index 7d5026b..5739a80 100644
--- a/src/shaders/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/shaders/gradients/SkTwoPointConicalGradient.cpp
@@ -12,6 +12,8 @@
 #include "SkWriteBuffer.h"
 #include "../../jumper/SkJumper.h"
 
+#include <utility>
+
 // Please see https://skia.org/dev/design/conical for how our shader works.
 
 bool SkTwoPointConicalGradient::FocalData::set(SkScalar r0, SkScalar r1, SkMatrix* matrix) {
@@ -134,16 +136,17 @@
     SkScalar r2 = buffer.readScalar();
 
     if (buffer.isVersionLT(SkReadBuffer::k2PtConicalNoFlip_Version) && buffer.readBool()) {
+        using std::swap;
         // legacy flipped gradient
-        SkTSwap(c1, c2);
-        SkTSwap(r1, r2);
+        swap(c1, c2);
+        swap(r1, r2);
 
         SkColor4f* colors = desc.mutableColors();
         SkScalar* pos = desc.mutablePos();
         const int last = desc.fCount - 1;
         const int half = desc.fCount >> 1;
         for (int i = 0; i < half; ++i) {
-            SkTSwap(colors[i], colors[last - i]);
+            swap(colors[i], colors[last - i]);
             if (pos) {
                 SkScalar tmp = pos[i];
                 pos[i] = SK_Scalar1 - pos[last - i];