Remove the GrGLInterface callback mechanism.

src/gpu/gl/GrGLInterface.cpp

 /*
  * 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/GrGLInterface.h"
 #include "gl/GrGLExtensions.h"
 #include "gl/GrGLUtil.h"
 
 #include <stdio.h>
 
-#if GR_GL_PER_GL_FUNC_CALLBACK
-namespace {
-void GrGLDefaultInterfaceCallback(const GrGLInterface*) {}
-}
-#endif
-
 const GrGLInterface* GrGLInterfaceAddTestDebugMarker(const GrGLInterface* interface,
                                                      GrGLInsertEventMarkerProc insertEventMarkerFn,
                                                      GrGLPushGroupMarkerProc pushGroupMarkerFn,
                                                      GrGLPopGroupMarkerProc popGroupMarkerFn) {
     GrGLInterface* newInterface = GrGLInterface::NewClone(interface);
 
     if (!newInterface->fExtensions.has("GL_EXT_debug_marker")) {
         newInterface->fExtensions.add("GL_EXT_debug_marker");
     }
 
@@ skipping 30 matching lines @@
     newInterface->fFunctions.fStencilThenCoverStrokePath = nullptr;
     newInterface->fFunctions.fStencilThenCoverFillPathInstanced = nullptr;
     newInterface->fFunctions.fStencilThenCoverStrokePathInstanced = nullptr;
     newInterface->fFunctions.fProgramPathFragmentInputGen = nullptr;
     newInterface->fFunctions.fBindFragmentInputLocation = nullptr;
     return newInterface;
 }
 
 GrGLInterface::GrGLInterface() {
     fStandard = kNone_GrGLStandard;
-
-#if GR_GL_PER_GL_FUNC_CALLBACK
-    fCallback = GrGLDefaultInterfaceCallback;
-    fCallbackData = 0;
-#endif
 }
 
 GrGLInterface* GrGLInterface::NewClone(const GrGLInterface* interface) {
     SkASSERT(interface);
 
     GrGLInterface* clone = new GrGLInterface;
     clone->fStandard = interface->fStandard;
     clone->fExtensions = interface->fExtensions;
     clone->fFunctions = interface->fFunctions;
-#if GR_GL_PER_GL_FUNC_CALLBACK
-    clone->fCallback = interface->fCallback;
-    clone->fCallbackData = interface->fCallbackData;
-#endif
     return clone;
 }
 
 #ifdef SK_DEBUG
     static int kIsDebug = 1;
 #else
     static int kIsDebug = 0;
 #endif
 
 #define RETURN_FALSE_INTERFACE                                                                   \
@@ skipping 695 matching lines @@
 
     if (fExtensions.has("EGL_KHR_image") || fExtensions.has("EGL_KHR_image_base")) {
         if (nullptr == fFunctions.fEGLCreateImage ||
             nullptr == fFunctions.fEGLDestroyImage) {
             RETURN_FALSE_INTERFACE
         }
     }
 
     return true;
 }