Revert of Move SkGLContext and some GrGLInterface implementations to skgputest module

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
new file mode 100644
index 0000000000000000000000000000000000000000..a2c5066273f823fb1c5289a035e5e8c51308be24
--- /dev/null
+++ b/src/gpu/gl/SkNullGLContext.cpp
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gl/SkNullGLContext.h"
+#include "gl/GrGLInterface.h"
+
+SkNullGLContext* SkNullGLContext::Create() {
+    SkNullGLContext* ctx = new SkNullGLContext;
+    if (!ctx->isValid()) {
+        delete ctx;
+        return nullptr;
+    }
+    return ctx;
+}
+
+SkNullGLContext::SkNullGLContext() {
+    this->init(GrGLCreateNullInterface());
+}
+
+SkNullGLContext::~SkNullGLContext() {
+    this->teardown();
+}