Add config options to run different GPU APIs to dm and nanobench

src/gpu/gl/SkNullGLContext.cpp

Index: src/gpu/gl/SkNullGLContext.cpp
diff --git a/src/gpu/gl/SkNullGLContext.cpp b/src/gpu/gl/SkNullGLContext.cpp
index e2a80ce2b37e72ca6f2c68c85f9a00090c6477b0..1ea388726a0d456e9eb3afee153b7aa82b65d9ca 100644
--- a/src/gpu/gl/SkNullGLContext.cpp
+++ b/src/gpu/gl/SkNullGLContext.cpp
@@ -532,10 +532,7 @@ static void set_current_context_from_interface(const GrGLInterface* interface) {
 }
 #endif
 
-SkNullGLContext* SkNullGLContext::Create(GrGLStandard forcedGpuAPI) {
-    if (kGLES_GrGLStandard == forcedGpuAPI) {
-        return nullptr;
-    }
+SkNullGLContext* SkNullGLContext::Create() {
     SkNullGLContext* ctx = new SkNullGLContext;
     if (!ctx->isValid()) {
         delete ctx;