Remove GrGLSLSampler type and subclasses

GrGLSLUniformManager and GrGLSLProgramDataManager subclasses handle sampler variation across GPU backends.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=5002

Change-Id: I968b006bab978c2fa209d1f7eda710c298d1212f
Reviewed-on: https://skia-review.googlesource.com/5002
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/glsl/GrGLSLProgramBuilder.h b/src/gpu/glsl/GrGLSLProgramBuilder.h
index 8a8cff5..7276144 100644
--- a/src/gpu/glsl/GrGLSLProgramBuilder.h
+++ b/src/gpu/glsl/GrGLSLProgramBuilder.h
@@ -16,7 +16,6 @@
 #include "glsl/GrGLSLPrimitiveProcessor.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 #include "glsl/GrGLSLUniformHandler.h"
-#include "glsl/GrGLSLSampler.h"
 #include "glsl/GrGLSLVertexShaderBuilder.h"
 #include "glsl/GrGLSLXferProcessor.h"
 
@@ -44,7 +43,13 @@
 
     typedef GrGLSLUniformHandler::SamplerHandle SamplerHandle;
 
-    const GrGLSLSampler& getSampler(SamplerHandle handle) const;
+    const GrGLSLShaderVar& samplerVariable(SamplerHandle handle) const {
+        return this->uniformHandler()->samplerVariable(handle);
+    }
+
+    GrSwizzle samplerSwizzle(SamplerHandle handle) const {
+        return this->uniformHandler()->samplerSwizzle(handle);
+    }
 
     // Handles for program uniforms (other than per-effect uniforms)
     struct BuiltinUniformHandles {