Revert of Initial version of external_oes texture support and unit test

include/gpu/gl/SkGLContext.h

Index: include/gpu/gl/SkGLContext.h
diff --git a/include/gpu/gl/SkGLContext.h b/include/gpu/gl/SkGLContext.h
index 3420a47973228594d4d1f8f6fc24cca9df685f3c..75cfcfee045896013f7c6dae3239ecc2e4f96683 100644
--- a/include/gpu/gl/SkGLContext.h
+++ b/include/gpu/gl/SkGLContext.h
@@ -14,9 +14,8 @@
 /**
  * Create an offscreen opengl context with an RGBA8 / 8bit stencil FBO.
  * Provides a GrGLInterface struct of function pointers for the context.
- * This class is intended for Skia's testing needs and not for general
- * use.
  */
+
 class SK_API SkGLContext : public SkRefCnt {
 public:
     ~SkGLContext() override;
@@ -36,16 +35,6 @@
     }
 
     void makeCurrent() const;
-
-    /** Used for testing EGLImage integration. Take a GL_TEXTURE_2D and wraps it in an EGL Image */
-    virtual GrEGLImage texture2DToEGLImage(GrGLuint /*texID*/) const { return 0; }
-    virtual void destroyEGLImage(GrEGLImage) const {}
-
-    /**
-     * Used for testing EGLImage integration. Takes a EGLImage and wraps it in a
-     * GL_TEXTURE_EXTERNAL_OES.
-     */
-    virtual GrGLuint eglImageToExternalTexture(GrEGLImage) const { return 0; }
 
     /**
      * The only purpose of this function it to provide a means of scheduling
@@ -69,12 +58,6 @@
      * context to test that further GL calls are not made by Skia GPU code.
      */
     void testAbandon();
-
-    /**
-     * Creates a new GL context of the same type and makes the returned context current
-     * (if not null).
-     */
-    virtual SkGLContext* createNew() const { return nullptr; }
 
     class GLFenceSync;  // SkGpuFenceSync implementation that uses the OpenGL functionality.