Make GrGLSLFragmentProcessors be created as std::unique_ptr.

Rename factory function from createGLSLInstance() to makeProgramImpl()

Bug: b/180759848
Bug: skia:11358
Change-Id: I095bdf1f26db5a8192fa8ab59000db4a1d561d96
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/373738
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp b/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp
index 3e0191c..a9c33f4 100644
--- a/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp
+++ b/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp
@@ -164,8 +164,9 @@
     Impl::GenKey(*this, caps, b);
 }
 
-GrGLSLFragmentProcessor* GrGaussianConvolutionFragmentProcessor::onCreateGLSLInstance() const {
-    return new Impl;
+std::unique_ptr<GrGLSLFragmentProcessor>
+GrGaussianConvolutionFragmentProcessor::onMakeProgramImpl() const {
+    return std::make_unique<Impl>();
 }
 
 bool GrGaussianConvolutionFragmentProcessor::onIsEqual(const GrFragmentProcessor& sBase) const {