Rename GrGpuGL to GrGLGpu for consistency

Review URL: https://codereview.chromium.org/808593003
diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index c5c31d3..06377c7 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -142,7 +142,7 @@
 bool GrGLProgramDescBuilder::Build(const GrOptDrawState& optState,
                                    const GrProgramDesc::DescInfo& descInfo,
                                    GrGpu::DrawType drawType,
-                                   GrGpuGL* gpu,
+                                   GrGLGpu* gpu,
                                    GrProgramDesc* desc) {
     // The descriptor is used as a cache key. Thus when a field of the
     // descriptor will not affect program generation (because of the attribute