Cherry pick two CLs back to M39 to fix a bug

include/core/SkMatrix.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 SkMatrix_DEFINED
@@ skipping 42 matching lines @@
         // only return the public masks
         return (TypeMask)(fTypeMask & 0xF);
     }
 
     /** Returns true if the matrix is identity.
     */
     bool isIdentity() const {
         return this->getType() == 0;
     }
 
+    bool isScaleTranslate() const {
+        return !(this->getType() & ~(kScale_Mask | kTranslate_Mask));
+    }
+
     /** Returns true if will map a rectangle to another rectangle. This can be
         true if the matrix is identity, scale-only, or rotates a multiple of
         90 degrees.
     */
     bool rectStaysRect() const {
         if (fTypeMask & kUnknown_Mask) {
             fTypeMask = this->computeTypeMask();
         }
         return (fTypeMask & kRectStaysRect_Mask) != 0;
     }
@@ skipping 638 matching lines @@
     static void RotTrans_pts(const SkMatrix&, SkPoint dst[], const SkPoint[],
                              int count);
     static void Persp_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], int);
 
     static const MapPtsProc gMapPtsProcs[];
 
     friend class SkPerspIter;
 };
 
 #endif