gpu: Add GpuFence framework.

ppapi/proxy/ppapi_command_buffer_proxy.h

 // 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.
 
 #ifndef PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_
 #define PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 58 matching lines @@
   void EnsureWorkVisible() override;
   gpu::CommandBufferNamespace GetNamespaceID() const override;
   gpu::CommandBufferId GetCommandBufferID() const override;
   uint64_t GenerateFenceSyncRelease() override;
   bool IsFenceSyncRelease(uint64_t release) override;
   bool IsFenceSyncFlushed(uint64_t release) override;
   bool IsFenceSyncFlushReceived(uint64_t release) override;
   void SignalSyncToken(const gpu::SyncToken& sync_token,
                        const base::Closure& callback) override;
   bool CanWaitUnverifiedSyncToken(const gpu::SyncToken* sync_token) override;
+  int32_t CreateFence(ClientFence fence) override;
+  void DestroyFence(int32_t id) override;
   int32_t GetExtraCommandBufferData() const override;
 
  private:
   bool Send(IPC::Message* msg);
   void UpdateState(const gpu::CommandBuffer::State& state, bool success);
 
   // Try to read an updated copy of the state from shared memory.
   void TryUpdateState();
 
   // The shared memory area used to update state.
@@ skipping 19 matching lines @@
   uint64_t flushed_fence_sync_release_;
   uint64_t validated_fence_sync_release_;
 
   DISALLOW_COPY_AND_ASSIGN(PpapiCommandBufferProxy);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif // PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_