sRGB support in Ganesh. Several pieces:

tests/ReadPixelsTest.cpp

Index: tests/ReadPixelsTest.cpp
diff --git a/tests/ReadPixelsTest.cpp b/tests/ReadPixelsTest.cpp
index b87d2b8ad7eff61700247cac3d6e86af2b1830f4..53533b71b02483736bd726045108e87bcc27177b 100644
--- a/tests/ReadPixelsTest.cpp
+++ b/tests/ReadPixelsTest.cpp
@@ -424,7 +424,8 @@ static void test_readpixels_texture(skiatest::Reporter* reporter, GrTexture* tex
                     GrPixelConfig dstConfig =
                             SkImageInfo2GrPixelConfig(gReadPixelsConfigs[c].fColorType,
                                                       gReadPixelsConfigs[c].fAlphaType,
-                                                      kLinear_SkColorProfileType);
+                                                      kLinear_SkColorProfileType,
+                                                      *texture->getContext()->caps());
                     uint32_t flags = 0;
                     if (gReadPixelsConfigs[c].fAlphaType == kUnpremul_SkAlphaType) {
                         flags = GrContext::kUnpremul_PixelOpsFlag;