respect srgb gamma when building mips

src/core/SkLightingShader.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapProcState.h"
 #include "SkColor.h"
 #include "SkEmptyShader.h"
@@ skipping 655 matching lines @@
     // computeTotalInverse was called in SkShader::createContext so we know it will succeed
     SkAssertResult(this->computeTotalInverse(rec, &diffTotalInv));
 
     SkMatrix normTotalInv;
     if (!this->computeNormTotalInverse(rec, &normTotalInv)) {
         return nullptr;
     }
 
     void* diffuseStateStorage = (char*)storage + sizeof(LightingShaderContext);
     SkBitmapProcState* diffuseState = new (diffuseStateStorage) SkBitmapProcState(fDiffuseMap,
-                                              SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
+                                              SkShader::kClamp_TileMode, SkShader::kClamp_TileMode,

[msarett, 2016/06/03 16:54:17]

nit: style?

+                                                                      SkMipMap::DeduceMode(rec));
     SkASSERT(diffuseState);
     if (!diffuseState->setup(diffTotalInv, *rec.fPaint)) {
         diffuseState->~SkBitmapProcState();
         return nullptr;
     }
 
     void* normalStateStorage = (char*)storage + sizeof(LightingShaderContext) + sizeof(SkBitmapProcState);
     SkBitmapProcState* normalState = new (normalStateStorage) SkBitmapProcState(fNormalMap,
-                                            SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
+                                            SkShader::kClamp_TileMode, SkShader::kClamp_TileMode,
+                                                                        SkMipMap::DeduceMode(rec));
     SkASSERT(normalState);
     if (!normalState->setup(normTotalInv, *rec.fPaint)) {
         diffuseState->~SkBitmapProcState();
         normalState->~SkBitmapProcState();
         return nullptr;
     }
 
     return new (storage) LightingShaderContext(*this, rec, diffuseState, normalState);
 }
 
@@ skipping 26 matching lines @@
                                             invNormRotation, diffLocalM, normLocalM);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkLightingShader)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkLightingShaderImpl)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
 
 ///////////////////////////////////////////////////////////////////////////////