Rename some processor functions from GL to GLSL

TBR=bsalomon@google.com

BUG=skia:

Review URL: https://codereview.chromium.org/1443743002
diff --git a/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp b/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
index f4429db..eff451a 100644
--- a/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
+++ b/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
@@ -670,12 +670,12 @@
     const SkMatrix& matrix() const { return fCoordTransform.getMatrix(); }
 
 private:
-    GrGLSLFragmentProcessor* onCreateGLInstance() const override {
+    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
         return new GrGLPerlinNoise2(*this);
     }
 
-    virtual void onGetGLProcessorKey(const GrGLSLCaps& caps,
-                                     GrProcessorKeyBuilder* b) const override {
+    virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
+                                       GrProcessorKeyBuilder* b) const override {
         GrGLPerlinNoise2::GenKey(*this, caps, b);
     }
 
@@ -1095,12 +1095,12 @@
     const SkMatrix& matrix() const { return fCoordTransform.getMatrix(); }
 
 private:
-    GrGLSLFragmentProcessor* onCreateGLInstance() const override {
+    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
         return new GrGLImprovedPerlinNoise(*this);
     }
 
-    virtual void onGetGLProcessorKey(const GrGLSLCaps& caps,
-                                     GrProcessorKeyBuilder* b) const override {
+    virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
+                                       GrProcessorKeyBuilder* b) const override {
         GrGLImprovedPerlinNoise::GenKey(*this, caps, b);
     }