Add DCHECK for nullptr in gl bindings

ui/gl/gl_bindings_autogen_osmesa.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file is auto-generated from
 // ui/gl/generate_bindings.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 44 matching lines @@
 
   if (g_debugBindingsInitialized)
     InitializeDebugBindings();
 }
 
 extern "C" {
 
 static void GL_BINDING_CALL Debug_OSMesaColorClamp(GLboolean enable) {
   GL_SERVICE_LOG("OSMesaColorClamp"
                  << "(" << GLEnums::GetStringBool(enable) << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaColorClampFn != nullptr);
   g_driver_osmesa.debug_fn.OSMesaColorClampFn(enable);
 }
 
 static OSMesaContext GL_BINDING_CALL
 Debug_OSMesaCreateContext(GLenum format, OSMesaContext sharelist) {
   GL_SERVICE_LOG("OSMesaCreateContext"
                  << "(" << GLEnums::GetStringEnum(format) << ", " << sharelist
                  << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaCreateContextFn != nullptr);
   OSMesaContext result =
       g_driver_osmesa.debug_fn.OSMesaCreateContextFn(format, sharelist);
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static OSMesaContext GL_BINDING_CALL
 Debug_OSMesaCreateContextExt(GLenum format,
                              GLint depthBits,
                              GLint stencilBits,
                              GLint accumBits,
                              OSMesaContext sharelist) {
   GL_SERVICE_LOG("OSMesaCreateContextExt"
                  << "(" << GLEnums::GetStringEnum(format) << ", " << depthBits
                  << ", " << stencilBits << ", " << accumBits << ", "
                  << sharelist << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaCreateContextExtFn != nullptr);
   OSMesaContext result = g_driver_osmesa.debug_fn.OSMesaCreateContextExtFn(
       format, depthBits, stencilBits, accumBits, sharelist);
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static void GL_BINDING_CALL Debug_OSMesaDestroyContext(OSMesaContext ctx) {
   GL_SERVICE_LOG("OSMesaDestroyContext"
                  << "(" << ctx << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaDestroyContextFn != nullptr);
   g_driver_osmesa.debug_fn.OSMesaDestroyContextFn(ctx);
 }
 
 static GLboolean GL_BINDING_CALL Debug_OSMesaGetColorBuffer(OSMesaContext c,
                                                             GLint* width,
                                                             GLint* height,
                                                             GLint* format,
                                                             void** buffer) {
   GL_SERVICE_LOG("OSMesaGetColorBuffer"
                  << "(" << c << ", " << static_cast<const void*>(width) << ", "
                  << static_cast<const void*>(height) << ", "
                  << static_cast<const void*>(format) << ", " << buffer << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaGetColorBufferFn != nullptr);
   GLboolean result = g_driver_osmesa.debug_fn.OSMesaGetColorBufferFn(
       c, width, height, format, buffer);
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static OSMesaContext GL_BINDING_CALL Debug_OSMesaGetCurrentContext(void) {
   GL_SERVICE_LOG("OSMesaGetCurrentContext"
                  << "("
                  << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaGetCurrentContextFn != nullptr);
   OSMesaContext result = g_driver_osmesa.debug_fn.OSMesaGetCurrentContextFn();
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static GLboolean GL_BINDING_CALL
 Debug_OSMesaGetDepthBuffer(OSMesaContext c,
                            GLint* width,
                            GLint* height,
                            GLint* bytesPerValue,
                            void** buffer) {
   GL_SERVICE_LOG("OSMesaGetDepthBuffer"
                  << "(" << c << ", " << static_cast<const void*>(width) << ", "
                  << static_cast<const void*>(height) << ", "
                  << static_cast<const void*>(bytesPerValue) << ", " << buffer
                  << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaGetDepthBufferFn != nullptr);
   GLboolean result = g_driver_osmesa.debug_fn.OSMesaGetDepthBufferFn(
       c, width, height, bytesPerValue, buffer);
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static void GL_BINDING_CALL Debug_OSMesaGetIntegerv(GLint pname, GLint* value) {
   GL_SERVICE_LOG("OSMesaGetIntegerv"
                  << "(" << pname << ", " << static_cast<const void*>(value)
                  << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaGetIntegervFn != nullptr);
   g_driver_osmesa.debug_fn.OSMesaGetIntegervFn(pname, value);
 }
 
 static OSMESAproc GL_BINDING_CALL
 Debug_OSMesaGetProcAddress(const char* funcName) {
   GL_SERVICE_LOG("OSMesaGetProcAddress"
                  << "(" << funcName << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaGetProcAddressFn != nullptr);
   OSMESAproc result = g_driver_osmesa.debug_fn.OSMesaGetProcAddressFn(funcName);
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static GLboolean GL_BINDING_CALL Debug_OSMesaMakeCurrent(OSMesaContext ctx,
                                                          void* buffer,
                                                          GLenum type,
                                                          GLsizei width,
                                                          GLsizei height) {
   GL_SERVICE_LOG("OSMesaMakeCurrent"
                  << "(" << ctx << ", " << static_cast<const void*>(buffer)
                  << ", " << GLEnums::GetStringEnum(type) << ", " << width
                  << ", " << height << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaMakeCurrentFn != nullptr);
   GLboolean result = g_driver_osmesa.debug_fn.OSMesaMakeCurrentFn(
       ctx, buffer, type, width, height);
   GL_SERVICE_LOG("GL_RESULT: " << result);
   return result;
 }
 
 static void GL_BINDING_CALL Debug_OSMesaPixelStore(GLint pname, GLint value) {
   GL_SERVICE_LOG("OSMesaPixelStore"
                  << "(" << pname << ", " << value << ")");
+  DCHECK(g_driver_osmesa.debug_fn.OSMesaPixelStoreFn != nullptr);
   g_driver_osmesa.debug_fn.OSMesaPixelStoreFn(pname, value);
 }
 }  // extern "C"
 
 void DriverOSMESA::InitializeDebugBindings() {
   if (!debug_fn.OSMesaColorClampFn) {
     debug_fn.OSMesaColorClampFn = fn.OSMesaColorClampFn;
     fn.OSMesaColorClampFn = Debug_OSMesaColorClamp;
   }
   if (!debug_fn.OSMesaCreateContextFn) {
@@ skipping 175 matching lines @@
   TRACE_EVENT_BINARY_EFFICIENT0("gpu", "TraceGLAPI::OSMesaMakeCurrent")
   return osmesa_api_->OSMesaMakeCurrentFn(ctx, buffer, type, width, height);
 }
 
 void TraceOSMESAApi::OSMesaPixelStoreFn(GLint pname, GLint value) {
   TRACE_EVENT_BINARY_EFFICIENT0("gpu", "TraceGLAPI::OSMesaPixelStore")
   osmesa_api_->OSMesaPixelStoreFn(pname, value);
 }
 
 }  // namespace gfx