sRGB support in Ganesh. Several pieces:

src/effects/gradients/SkGradientShader.cpp

Index: src/effects/gradients/SkGradientShader.cpp
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 9fe6c91a018ebcdcad364c344914dfc0c77631ff..6a8befd81d8fbae1c489d34d853215414e977004 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -12,6 +12,8 @@
 #include "SkTwoPointConicalGradient.h"
 #include "SkSweepGradient.h"
 
+#include "GrContext.h"
+
 void SkGradientShaderBase::Descriptor::flatten(SkWriteBuffer& buffer) const {
     buffer.writeColorArray(fColors, fCount);
     if (fPos) {
@@ -1117,7 +1119,7 @@ GrGradientEffect::GrGradientEffect(GrContext* ctx,
         desc.fHeight = 32;
         desc.fRowHeight = bitmap.height();
         desc.fContext = ctx;
-        desc.fConfig = SkImageInfo2GrPixelConfig(bitmap.info());
+        desc.fConfig = SkImageInfo2GrPixelConfig(bitmap.info(), *ctx->caps());
         fAtlas = GrTextureStripAtlas::GetAtlas(desc);
         SkASSERT(fAtlas);