Split tracking of TexelBuffers from normal samplers

This is precursor CL to add support for texel buffers in Vulkan.

This change as includes fixes to the ordering of assigning
locations and texture units so that they match in
GrGLProgramDataManager and GrGLProgram.

Bug: skia:
Change-Id: I30c9578fb7dcb187256f744e07651e8564f93a6b
Reviewed-on: https://skia-review.googlesource.com/15225
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/gl/GrGLProgramDataManager.h b/src/gpu/gl/GrGLProgramDataManager.h
index 42e0656..6b4e4d9 100644
--- a/src/gpu/gl/GrGLProgramDataManager.h
+++ b/src/gpu/gl/GrGLProgramDataManager.h
@@ -45,9 +45,8 @@
     GrGLProgramDataManager(GrGLGpu*, GrGLuint programID, const UniformInfoArray&,
                            const VaryingInfoArray&);
 
-
-    void setSamplers(const UniformInfoArray& samplers) const;
-    void setImageStorages(const UniformInfoArray &images) const;
+    void setSamplerUniforms(const UniformInfoArray& samplers, int startUnit) const;
+    void setImageStorages(const UniformInfoArray& images) const;
 
     /** Functions for uploading uniform values. The varities ending in v can be used to upload to an
     *  array of uniforms. arrayCount must be <= the array count of the uniform.