Initial version of external_oes texture support and unit test

include/gpu/gl/angle/SkANGLEGLContext.h

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkANGLEGLContext_DEFINED
 #define SkANGLEGLContext_DEFINED
 
 #if SK_ANGLE
 
 #include "gl/SkGLContext.h"
 
 class SkANGLEGLContext : public SkGLContext {
 public:
     ~SkANGLEGLContext() override;
 
     static SkANGLEGLContext* Create(GrGLStandard forcedGpuAPI, bool useGLBackend) {
         if (kGL_GrGLStandard == forcedGpuAPI) {
             return NULL;
         }
         SkANGLEGLContext* ctx = new SkANGLEGLContext(useGLBackend);
         if (!ctx->isValid()) {
             delete ctx;
             return NULL;
         }
         return ctx;
     }
+    GrEGLImage texture2DToEGLImage(GrGLuint texID) const override;
+    void destroyEGLImage(GrEGLImage) const override;
+    GrGLuint eglImageToExternalTexture(GrEGLImage) const override;
+    SkGLContext* createNew() const override;
 
     // The param is an EGLNativeDisplayType and the return is an EGLDispay.
     static void* GetD3DEGLDisplay(void* nativeDisplay, bool useGLBackend);
 
 private:
     SkANGLEGLContext(bool preferGLBackend);
     void destroyGLContext();
 
     void onPlatformMakeCurrent() const override;
     void onPlatformSwapBuffers() const override;
     GrGLFuncPtr onPlatformGetProcAddress(const char* name) const override;
 
     void* fContext;
     void* fDisplay;
     void* fSurface;
+    bool  fIsGLBackend;
 };
 
 #endif
 
 #endif