Add SkSourceGammaTreatment enum so we know how to create mips

gm/dcshader.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #if SK_SUPPORT_GPU
 #include "GrFragmentProcessor.h"
@@ skipping 20 matching lines @@
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(DCShader);
 
     void flatten(SkWriteBuffer& buf) const override {
         buf.writeMatrix(fDeviceMatrix);
     }
 
     const GrFragmentProcessor* asFragmentProcessor(GrContext*,
                                                    const SkMatrix& viewM,
                                                    const SkMatrix* localMatrix,
-                                                   SkFilterQuality) const override;
+                                                   SkFilterQuality,
+                                                   SkSourceGammaTreatment) const override;
 
 #ifndef SK_IGNORE_TO_STRING
     void toString(SkString* str) const override {
         str->appendf("DCShader: ()");
     }
 #endif
 
 private:
     const SkMatrix fDeviceMatrix;
 };
@@ skipping 42 matching lines @@
                                GrProcessorKeyBuilder* b) const override {}
 
     bool onIsEqual(const GrFragmentProcessor&) const override { return true; }
 
     GrCoordTransform fDeviceTransform;
 };
 
 const GrFragmentProcessor* DCShader::asFragmentProcessor(GrContext*,
                                                          const SkMatrix& viewM,
                                                          const SkMatrix* localMatrix,
-                                                         SkFilterQuality) const {
+                                                         SkFilterQuality,
+                                                         SkSourceGammaTreatment) const {
     SkAutoTUnref<const GrFragmentProcessor> inner(new DCFP(fDeviceMatrix));
     return GrFragmentProcessor::MulOutputByInputAlpha(inner);
 }
 
 class DCShaderGM : public GM {
 public:
     DCShaderGM() {
         this->setBGColor(sk_tool_utils::color_to_565(0xFFAABBCC));
     }
 
@@ skipping 175 matching lines @@
     };
 
     SkTArray<Prim*> fPrims;
 
     typedef GM INHERITED;
 };
 
 DEF_GM(return new DCShaderGM;)
 }
 #endif