gpu: Add GpuFence framework.

gpu/command_buffer/service/fence_manager.cc

+// Copyright 2016 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/fence_manager.h"
+
+#include <stdint.h>
+
+#include "base/logging.h"
+#include "ui/gl/gl_fence.h"
+
+namespace gpu {
+namespace gles2 {
+
+FenceManager::FenceManager() {}
+
+FenceManager::~FenceManager() {}
+
+void FenceManager::Destroy(bool have_context) {
+  if (!have_context) {
+    for (auto& fence_entry : fences_)
+      fence_entry.second.get()->Invalidate();
+  }
+  fences_.clear();
+}
+
+void FenceManager::AddFence(std::unique_ptr<gl::GLFence> fence,
+                            int32_t service_id) {
+  DCHECK(fences_.find(service_id) == fences_.end());
+  fences_[service_id] = std::move(fence);
+}
+
+void FenceManager::RemoveFence(int32_t service_id) {
+  GLFenceMap::iterator iter = fences_.find(service_id);
+  DCHECK(iter != fences_.end());
+  fences_.erase(iter);
+}
+
+gl::GLFence* FenceManager::LookupFence(int32_t service_id) {
+  GLFenceMap::const_iterator iter = fences_.find(service_id);
+  if (iter != fences_.end())
+    return iter->second.get();
+
+  return NULL;
+}
+
+}  // namespace gles2
+}  // namespace gpu