Refactor GL bindings so there is no global GLApi or DriverGL.

gpu/command_buffer/service/program_manager.cc

 // Copyright (c) 2012 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.
 
 #include "gpu/command_buffer/service/program_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1365 matching lines @@
     }
 
     ExecuteBindAttribLocationCalls();
     if (!ExecuteTransformFeedbackVaryingsCall()) {
       return false;
     }
 
     ExecuteProgramOutputBindCalls();
 
     before_time = TimeTicks::Now();
-    if (cache && gl::g_driver_gl.ext.b_GL_ARB_get_program_binary) {
+    if (cache && gl::g_current_gl_driver->ext.b_GL_ARB_get_program_binary) {
       glProgramParameteri(service_id(),
                           PROGRAM_BINARY_RETRIEVABLE_HINT,
                           GL_TRUE);
     }
     glLinkProgram(service_id());
   }
 
   GLint success = 0;
   glGetProgramiv(service_id(), GL_LINK_STATUS, &success);
   if (success == GL_TRUE) {
@@ skipping 1263 matching lines @@
   DCHECK(program);
   program->ClearUniforms(&zero_);
 }
 
 int32_t ProgramManager::MakeFakeLocation(int32_t index, int32_t element) {
   return index + element * 0x10000;
 }
 
 }  // namespace gles2
 }  // namespace gpu