Add SkSourceGammaTreatment enum so we know how to create mips

src/effects/gradients/SkTwoPointConicalGradient.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTwoPointConicalGradient.h"
 #include "SkTwoPointConicalGradient_gpu.h"
 
@@ skipping 342 matching lines @@
 }
 
 #if SK_SUPPORT_GPU
 
 #include "SkGr.h"
 
 const GrFragmentProcessor* SkTwoPointConicalGradient::asFragmentProcessor(
                                                   GrContext* context,
                                                   const SkMatrix& viewM,
                                                   const SkMatrix* localMatrix,
-                                                  SkFilterQuality) const {
+                                                  SkFilterQuality,
+                                                  SkSourceGammaTreatment) const {
     SkASSERT(context);
     SkASSERT(fPtsToUnit.isIdentity());
     SkAutoTUnref<const GrFragmentProcessor> inner(
         Gr2PtConicalGradientEffect::Create(context, *this, fTileMode, localMatrix));
     return GrFragmentProcessor::MulOutputByInputAlpha(inner);
 }
 
 #endif
 
 #ifndef SK_IGNORE_TO_STRING
@@ skipping 14 matching lines @@
     str->appendScalar(fCenter2.fY);
     str->append(") radius2: ");
     str->appendScalar(fRadius2);
     str->append(" ");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif