Add SkTPin.

include/core/SkScalar.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkScalar_DEFINED
 #define SkScalar_DEFINED
 
@@ skipping 157 matching lines @@
     return (int)floor(xx);
 }
 
 static inline SkScalar SkScalarClampMax(SkScalar x, SkScalar max) {
     x = SkTMin(x, max);
     x = SkTMax<SkScalar>(x, 0);
     return x;
 }
 
 static inline SkScalar SkScalarPin(SkScalar x, SkScalar min, SkScalar max) {
-    x = SkTMin(x, max);
-    x = SkTMax(x, min);
-    return x;
+    return SkTPin(x, min, max);
 }
 
 SkScalar SkScalarSinCos(SkScalar radians, SkScalar* cosValue);
 
 static inline SkScalar SkScalarSquare(SkScalar x) { return x * x; }
 
 #define SkScalarMul(a, b)       ((SkScalar)(a) * (b))
 #define SkScalarMulAdd(a, b, c) ((SkScalar)(a) * (b) + (c))
 #define SkScalarDiv(a, b)       ((SkScalar)(a) / (b))
 #define SkScalarMulDiv(a, b, c) ((SkScalar)(a) * (b) / (c))
@@ skipping 72 matching lines @@
     SkASSERT(n >= 0);
     for (int i = 0; i < n; ++i) {
         if (a[i] != b[i]) {
             return false;
         }
     }
     return true;
 }
 
 #endif