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/builders/GrGLProgramBuilder.cpp b/src/gpu/gl/builders/GrGLProgramBuilder.cpp
index a82bccb..8e662b9 100644
--- a/src/gpu/gl/builders/GrGLProgramBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLProgramBuilder.cpp
@@ -259,6 +259,7 @@
                            programID,
                            fUniformHandler.fUniforms,
                            fUniformHandler.fSamplers,
+                           fUniformHandler.fTexelBuffers,
                            fUniformHandler.fImageStorages,
                            fVaryingHandler.fPathProcVaryingInfos,
                            fGeometryProcessor,