Revert of Add OpenGL context to Viewer.

tools/viewer/sk_app/GLWindowContext.h

Index: tools/viewer/sk_app/GLWindowContext.h
diff --git a/tools/viewer/sk_app/GLWindowContext.h b/tools/viewer/sk_app/GLWindowContext.h
deleted file mode 100644
index 6fb5e0988924bd28d37095f793cc7328e9166cc9..0000000000000000000000000000000000000000
--- a/tools/viewer/sk_app/GLWindowContext.h
+++ /dev/null
@@ -1,63 +0,0 @@
-
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#ifndef GLWindowContext_DEFINED
-#define GLWindowContext_DEFINED
-
-
-#include "gl/GrGLInterface.h"
-
-#include "SkRefCnt.h"
-#include "GrRenderTarget.h"
-#include "SkSurface.h"
-
-#include "WindowContext.h"
-
-class GrContext;
-
-namespace sk_app {
-
-class GLWindowContext : public WindowContext {
-public:
-    // This is defined in the platform .cpp file
-    static GLWindowContext* Create(void* platformData, const DisplayParams& params);
-
-    sk_sp<SkSurface> getBackbufferSurface() override;
-
-    bool isValid() override { return SkToBool(fBackendContext.get()); }
-
-    void resize(uint32_t w, uint32_t h) override;
-    void swapBuffers() override;
-
-    void setDisplayParams(const DisplayParams& params) override;
-
-    GrBackendContext getBackendContext() override {
-        return (GrBackendContext) fBackendContext.get();
-    }
-
-protected:
-    GLWindowContext(void*, const DisplayParams&);
-    void initializeContext(void*, const DisplayParams&);
-    virtual void onInitializeContext(void*, const DisplayParams&) = 0;
-    void destroyContext();
-    virtual void onDestroyContext() = 0;
-    virtual void onSwapBuffers() = 0;
-
-    SkAutoTUnref<const GrGLInterface> fBackendContext;
-    sk_sp<GrRenderTarget>             fRenderTarget;
-    sk_sp<SkSurface>                  fSurface;
-
-    // parameters obtained from the native window
-    int                               fSampleCount;
-    int                               fStencilBits;
-    int                               fColorBits;
-    int                               fActualColorBits;
-};
-
-}   // namespace sk_app
-
-#endif