These two new types are in support of Vulkan and the ability to send
separate texture and sampler uniforms to the shader. They don't really fit
well in the current system, since the current system ties together to idea
of intended use and how to emit shader code into the same GrSLType enum.
In vulkan, I want the GrGLSLSampler object to be used as a Sampler2D, but
when appending its declaration it will emit a Texture2D and sampler object.
Our query for GrSLTypeIsSamplerType refers more to the combination of texture
and sampler and not just the sampler part. The GrSLTypeIs2DTextureType query
is for is a a SamplerType that uses Texture2Ds. My new types don't really fit
into either these categories as they are just half of the whole.
In some refactoring down the road (possibly connected with SkSL), I suggest we
split apart the concept of how we intend to use a GrGLSLSampler (Sampler2D, SamplerBuffer,
etc.), from how we actually add it to the code (sampler, texture2D, sampler2D, etc.).
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2143143002
Review-Url: https://codereview.chromium.org/2143143002
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