sRGB support in Ganesh. Several pieces:

src/image/SkImage_Gpu.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 "SkAutoPixmapStorage.h"
 #include "GrCaps.h"
 #include "GrContext.h"
@@ skipping 93 matching lines @@
     for (int y = 0; y < info.height(); ++y) {
         for (int x = 0; x < info.width(); ++x) {
             row[x] = SkPreMultiplyColor(row[x]);
         }
     }
 }
 
 bool SkImage_Gpu::onReadPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                                int srcX, int srcY, CachingHint) const {
     GrPixelConfig config = SkImageInfo2GrPixelConfig(info.colorType(), info.alphaType(),
-                                                     info.profileType());
+                                                     info.profileType(),
+                                                     *fTexture->getContext()->caps());
     uint32_t flags = 0;
     if (kUnpremul_SkAlphaType == info.alphaType() && kPremul_SkAlphaType == fAlphaType) {
         // let the GPU perform this transformation for us
         flags = GrContext::kUnpremul_PixelOpsFlag;
     }
     if (!fTexture->readPixels(srcX, srcY, info.width(), info.height(), config,
                               pixels, rowBytes, flags)) {
         return false;
     }
     // do we have to manually fix-up the alpha channel?
@@ skipping 325 matching lines @@
         return nullptr;
     }
 
     const SkIRect srcR = SkIRect::MakeWH(desc.fWidth, desc.fHeight);
     const SkIPoint dstP = SkIPoint::Make(0, 0);
     ctx->copySurface(dst, src, srcR, dstP);
     ctx->flushSurfaceWrites(dst);
     return dst;
 }