Plumb dst color space in many places, rather than "mode"

This is less to type in most cases, and gives us more information
(for things like picture-backed images, where we need to know all
about the destination surface).

Additionally, strip out the plumbing entirely for bitmap sources,
where we don't need to know anything.

BUG=skia:

Change-Id: I4deff6c7c345fcf62eb08b2aff0560adae4313da
Reviewed-on: https://skia-review.googlesource.com/5748
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 507fbe4..df78da9 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1662,9 +1662,7 @@
                 fCoordTransform.reset(*args.fMatrix, fAtlas->getTexture(), params.filterMode());
                 fTextureSampler.reset(fAtlas->getTexture(), params);
             } else {
-                sk_sp<GrTexture> texture(GrRefCachedBitmapTexture(
-                                          args.fContext, bitmap, params,
-                                          SkDestinationSurfaceColorMode::kGammaAndColorSpaceAware));
+                sk_sp<GrTexture> texture(GrRefCachedBitmapTexture(args.fContext, bitmap, params));
                 if (!texture) {
                     return;
                 }