Added booleans that indicate which GL extensions are available.

gpu/command_buffer/service/gpu_scheduler.cc

 // Copyright (c) 2011 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/gpu_scheduler.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 44 matching lines @@
 
   DCHECK(IsScheduled());
 
   CommandBuffer::State state = command_buffer_->GetState();
   parser_->set_put(state.put_offset);
   if (state.error != error::kNoError)
     return;
 
   // Check that the GPU has passed all fences.
   if (!unschedule_fences_.empty()) {
-    if (glGenFencesNV) {
+    if (gfx::g_GL_NV_fence) {
       while (!unschedule_fences_.empty()) {
         if (glTestFenceNV(unschedule_fences_.front().fence)) {
           glDeleteFencesNV(1, &unschedule_fences_.front().fence);
           unschedule_fences_.front().task.Run();
           unschedule_fences_.pop();
         } else {
           SetScheduled(false);
           MessageLoop::current()->PostDelayedTask(
               FROM_HERE,
               base::Bind(&GpuScheduler::SetScheduled, AsWeakPtr(), true),
@@ skipping 98 matching lines @@
   // PutChanged will treat the fence as having been crossed and thereby not
   // poll indefinately. See spec:
   // http://www.opengl.org/registry/specs/NV/fence.txt
   //
   // What should happen if TestFenceNV is called for a name before SetFenceNV
   // is called?
   //     We generate an INVALID_OPERATION error, and return TRUE.
   //     This follows the semantics for texture object names before
   //     they are bound, in that they acquire their state upon binding.
   //     We will arbitrarily return TRUE for consistency.
-  if (glGenFencesNV) {
+  if (gfx::g_GL_NV_fence) {
     glGenFencesNV(1, &fence.fence);
     glSetFenceNV(fence.fence, GL_ALL_COMPLETED_NV);
   }
 
   glFlush();
 
   fence.task = task;
 
   unschedule_fences_.push(fence);
 }
 
 GpuScheduler::UnscheduleFence::UnscheduleFence() : fence(0) {
 }
 
 GpuScheduler::UnscheduleFence::~UnscheduleFence() {
 }
 
 }  // namespace gpu