Cleanup some sRGB TODOs, mostly around setting GrPaint flags correctly

src/core/SkSpecialSurface.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file
  */
 
 #include "SkCanvas.h"
 #include "SkSpecialImage.h"
 #include "SkSpecialSurface.h"
@@ skipping 119 matching lines @@
         fCanvas.reset(new SkCanvas(device.get()));
         fCanvas->clipRect(SkRect::Make(subset));
 #ifdef SK_IS_BOT
         fCanvas->clear(SK_ColorRED);  // catch any imageFilter sloppiness
 #endif
     }
 
     ~SkSpecialSurface_Gpu() override { }
 
     sk_sp<SkSpecialImage> onMakeImageSnapshot() override {
-        // TODO: Supply color space from fDrawContext, once it's present
-        sk_sp<SkSpecialImage> tmp(SkSpecialImage::MakeFromGpu(this->subset(),
-                                                              kNeedNewImageUniqueID_SpecialImage,
-                                                              fDrawContext->asTexture(),
-                                                              nullptr,
-                                                              &this->props()));
+        sk_sp<SkSpecialImage> tmp(SkSpecialImage::MakeFromGpu(
+                                                           this->subset(),
+                                                           kNeedNewImageUniqueID_SpecialImage,
+                                                           fDrawContext->asTexture(),
+                                                           sk_ref_sp(fDrawContext->getColorSpace()),
+                                                           &this->props()));
         fDrawContext = nullptr;
         return tmp;
     }
 
 private:
     sk_sp<GrDrawContext> fDrawContext;
 
     typedef SkSpecialSurface_Base INHERITED;
 };
 
@@ skipping 11 matching lines @@
     if (!drawContext) {
         return nullptr;
     }
 
     const SkIRect subset = SkIRect::MakeWH(width, height);
 
     return sk_make_sp<SkSpecialSurface_Gpu>(std::move(drawContext), width, height, subset);
 }
 
 #endif