Add SkSourceGammaTreatment enum so we know how to create mips

src/gpu/SkGpuDevice_drawTexture.cpp

Index: src/gpu/SkGpuDevice_drawTexture.cpp
diff --git a/src/gpu/SkGpuDevice_drawTexture.cpp b/src/gpu/SkGpuDevice_drawTexture.cpp
index 5eecf43e8338b6058d52edfa57b79b0268f635b8..c553a5861cc80097e6aa17429c44bf9b742a50c1 100644
--- a/src/gpu/SkGpuDevice_drawTexture.cpp
+++ b/src/gpu/SkGpuDevice_drawTexture.cpp
@@ -201,15 +201,17 @@ void SkGpuDevice::drawTextureProducerImpl(GrTextureProducer* producer,
         }
         textureMatrix = &tempMatrix;
     }
+    bool gammaCorrect = this->surfaceProps().isGammaCorrect();
     SkAutoTUnref<const GrFragmentProcessor> fp(producer->createFragmentProcessor(
-        *textureMatrix, clippedSrcRect, constraintMode, coordsAllInsideSrcRect, filterMode));
+        *textureMatrix, clippedSrcRect, constraintMode, coordsAllInsideSrcRect, filterMode,
+        gammaCorrect));
     if (!fp) {
         return;
     }
 
     GrPaint grPaint;
     if (!SkPaintToGrPaintWithTexture(fContext, paint, viewMatrix, fp, producer->isAlphaOnly(),
-                                     this->surfaceProps().isGammaCorrect(), &grPaint)) {
+                                     gammaCorrect, &grPaint)) {
         return;
     }