Gradient shaders: make fPtsToUnit const, pre-cache getType().

src/effects/gradients/SkGradientShader.cpp

 /*
  * 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.
  */
 
 #include "SkGradientShaderPriv.h"
 #include "SkLinearGradient.h"
 #include "SkRadialGradient.h"
@@ skipping 49 matching lines @@
         fLocalMatrix = &fLocalMatrixStorage;
         buffer.readMatrix(&fLocalMatrixStorage);
     } else {
         fLocalMatrix = NULL;
     }
     return buffer.isValid();
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////
 
-SkGradientShaderBase::SkGradientShaderBase(const Descriptor& desc)
+SkGradientShaderBase::SkGradientShaderBase(const Descriptor& desc, const SkMatrix& ptsToUnit)
     : INHERITED(desc.fLocalMatrix)
+    , fPtsToUnit(ptsToUnit)
 {
+    fPtsToUnit.getType();  // Precache so reads are threadsafe.
     SkASSERT(desc.fCount > 1);
 
     fGradFlags = SkToU8(desc.fGradFlags);
 
     SkASSERT((unsigned)desc.fTileMode < SkShader::kTileModeCount);
     SkASSERT(SkShader::kTileModeCount == SK_ARRAY_COUNT(gTileProcs));
     fTileMode = desc.fTileMode;
     fTileProc = gTileProcs[desc.fTileMode];
 
     /*  Note: we let the caller skip the first and/or last position.
@@ skipping 1097 matching lines @@
             (*stops)[i] = stop;
             stop = i < outColors - 1 ? stop + random->nextUScalar1() * (1.f - stop) : 1.f;
         }
     }
     *tm = static_cast<SkShader::TileMode>(random->nextULessThan(SkShader::kTileModeCount));
 
     return outColors;
 }
 
 #endif