Make SkImage_Lazy::onMakeColorSpace return a SkImage_Lazy

Make SkImage_Lazy::onMakeColorSpace return a new SkImage_Lazy
with the color space of SkImage_Lazy::fInfo changed.

Update the call to SkImageGenerator::getPixels to specify
image info with this new color space.

Update the call to SkImageGenerator::generateTexture to specify
this new color space. Update SkPictureImageGenerator to respect
the color space argument. Add a SkTransferFunctionBehavior
argument to SkImageGenerator::generateTexture to indicate if
color conversion is to be doing using an xform canvas.

Update Generator_GrYUVProvider::refAsTextureProxy to include a
color conversion step to respect this new color space.

TBR=reed@google.com
Bug:739559
Change-Id: I156a858884659e9dfae739a653bab2ef89274959
Reviewed-on: https://skia-review.googlesource.com/21605
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Christopher Cameron <ccameron@chromium.org>
Reviewed-by: Christopher Cameron <ccameron@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
14 files changed