Reset context after doing non-Skia GL rendering.

Fixes nanobench crash in GLInstancedArraysBench

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1969623003

Review-Url: https://codereview.chromium.org/1969623003
diff --git a/bench/GLBench.cpp b/bench/GLBench.cpp
index f184d77..524bfe1 100644
--- a/bench/GLBench.cpp
+++ b/bench/GLBench.cpp
@@ -56,6 +56,7 @@
         return;
     }
     this->glDraw(loops, ctx);
+    canvas->getGrContext()->resetContext();
 }
 
 GrGLuint GLBench::CompileShader(const GrGLInterface* gl, const char* shaderSrc, GrGLenum type) {