Implement texel buffers

Adds a mechanism for processors to add buffer accesses and implements
them in the GL backend.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1870893002

Review URL: https://codereview.chromium.org/1870893002

1 files changed, 8 insertions, 1 deletions

diff --git a/src/gpu/glsl/GrGLSLProgramBuilder.h b/src/gpu/glsl/GrGLSLProgramBuilder.h
index 4d253c73bf..3ce7daf349 100644
--- a/src/gpu/glsl/GrGLSLProgramBuilder.h
+++ b/src/gpu/glsl/GrGLSLProgramBuilder.h
@@ -146,7 +146,14 @@ private:
                                 const GrGLSLExpr4& coverageIn,
                                 bool ignoresCoverage,
                                 GrPixelLocalStorageState plsState);
-    void emitSamplers(const GrProcessor& processor, GrGLSLSampler::SamplerArray* outTexSamplers);
+    void emitSamplers(const GrProcessor& processor,
+                      GrGLSLSampler::SamplerArray* outTexSamplers,
+                      GrGLSLSampler::SamplerArray* outBufferSamplers);
+    void emitSampler(GrSLType samplerType,
+                     GrPixelConfig,
+                     const char* name,
+                     GrShaderFlags visibility,
+                     GrGLSLSampler::SamplerArray* outSamplers);
     void emitFSOutputSwizzle(bool hasSecondaryOutput);
     bool checkSamplerCounts();