rename sk_gpu_test::GLContext to sk_gpu_test::GLTestContext

rename subclasses

Fix up the EGL native GLTestContext
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1849463002

TBR=jvanverth@google.com

Committed: https://skia.googlesource.com/skia/+/4c7f0a16312c374eba4e8d5d46435ce9eb0b9971

Review URL: https://codereview.chromium.org/1849463002
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index 5bf28aa..d4cf1cc 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -39,7 +39,7 @@
 #   include "GrContext.h"
 #   include "SkGpuDevice.h"
 #   if SK_ANGLE
-#       include "gl/angle/GLContext_angle.h"
+#       include "gl/angle/GLTestContext_angle.h"
 #   endif
 #else
 class GrContext;