Move SkGLContext and some GrGLInterface implementations to skgputest module

src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp

-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "gl/GrGLInterface.h"
-#include "gl/GrGLAssembleInterface.h"
-#include "../ports/SkOSLibrary.h"
-
-#include <EGL/egl.h>
-
-namespace {
-struct Libs {
-    void* fGLLib;
-    void* fEGLLib;
-};
-}
-
-static GrGLFuncPtr angle_get_gl_proc(void* ctx, const char name[]) {
-    const Libs* libs = reinterpret_cast<const Libs*>(ctx);
-    GrGLFuncPtr proc = (GrGLFuncPtr) GetProcedureAddress(libs->fGLLib, name);
-    if (proc) {
-        return proc;
-    }
-    proc = (GrGLFuncPtr) GetProcedureAddress(libs->fEGLLib, name);
-    if (proc) {
-        return proc;
-    }
-    return eglGetProcAddress(name);
-}
-
-const GrGLInterface* GrGLCreateANGLEInterface() {
-    static Libs gLibs = { nullptr, nullptr };
-
-    if (nullptr == gLibs.fGLLib) {
-        // We load the ANGLE library and never let it go
-#if defined _WIN32
-        gLibs.fGLLib = DynamicLoadLibrary("libGLESv2.dll");
-        gLibs.fEGLLib = DynamicLoadLibrary("libEGL.dll");
-#elif defined SK_BUILD_FOR_MAC
-        gLibs.fGLLib = DynamicLoadLibrary("libGLESv2.dylib");
-        gLibs.fEGLLib = DynamicLoadLibrary("libEGL.dylib");
-#else
-        gLibs.fGLLib = DynamicLoadLibrary("libGLESv2.so");
-        gLibs.fEGLLib = DynamicLoadLibrary("libEGL.so");
-#endif
-    }
-
-    if (nullptr == gLibs.fGLLib || nullptr == gLibs.fEGLLib) {
-        // We can't setup the interface correctly w/o the so
-        return nullptr;
-    }
-
-    return GrGLAssembleGLESInterface(&gLibs, angle_get_gl_proc);
-}