sRGB support in Ganesh. Several pieces:

src/gpu/gl/GrGLGpu.h

Index: src/gpu/gl/GrGLGpu.h
diff --git a/src/gpu/gl/GrGLGpu.h b/src/gpu/gl/GrGLGpu.h
index 39d565987d025ad9a5168dcf4ba6ae3e560fede0..0d43b3e10dc0a05b4be7b359a059ce13c94ab695 100644
--- a/src/gpu/gl/GrGLGpu.h
+++ b/src/gpu/gl/GrGLGpu.h
@@ -59,7 +59,8 @@ public:
     void discard(GrRenderTarget*) override;
 
     // Used by GrGLProgram to configure OpenGL state.
-    void bindTexture(int unitIdx, const GrTextureParams& params, GrGLTexture* texture);
+    void bindTexture(int unitIdx, const GrTextureParams& params, bool allowSRGB,

[bsalomon, 2016/03/17 18:51:18]

Should we make the param name clearly associated with the dst? e.g.
dstConfigAllowsSRGB?

It's ok to use an ugly long name when we're doing an ugly complicated thing.

+                     GrGLTexture* texture);
 
     bool onGetReadPixelsInfo(GrSurface* srcSurface, int readWidth, int readHeight, size_t rowBytes,
                              GrPixelConfig readConfig, DrawPreference*,