Introducing gpu::CommandBufferId as a distinct, IdType<...>-based type.

gpu/command_buffer/client/gpu_control.h

 // 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.
 
 #ifndef GPU_COMMAND_BUFFER_CLIENT_GPU_CONTROL_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GPU_CONTROL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "gpu/command_buffer/common/capabilities.h"
+#include "gpu/command_buffer/common/command_buffer_id.h"
 #include "gpu/command_buffer/common/constants.h"
 #include "gpu/command_buffer/common/mailbox.h"
 #include "gpu/gpu_export.h"
 
 extern "C" typedef struct _ClientBuffer* ClientBuffer;
 
 namespace base {
 class Lock;
 }
 
@@ skipping 50 matching lines @@
   // services and will be treated as a NOP for in process command buffers.
   virtual void EnsureWorkVisible() = 0;
 
   // The namespace and command buffer ID forms a unique pair for all existing
   // GpuControl (on client) and matches for the corresponding command buffer
   // (on server) in a single server process. The extra command buffer data can
   // be used for extra identification purposes. One usage is to store some
   // extra field to identify unverified sync tokens for the implementation of
   // the CanWaitUnverifiedSyncToken() function.
   virtual CommandBufferNamespace GetNamespaceID() const = 0;
-  virtual uint64_t GetCommandBufferID() const = 0;
+  virtual CommandBufferId GetCommandBufferID() const = 0;
   virtual int32_t GetExtraCommandBufferData() const = 0;
 
   // Fence Syncs use release counters at a context level, these fence syncs
   // need to be flushed before they can be shared with other contexts across
   // channels. Subclasses should implement these functions and take care of
   // figuring out when a fence sync has been flushed. The difference between
   // IsFenceSyncFlushed and IsFenceSyncFlushReceived, one is testing is the
   // client has issued the flush, and the other is testing if the service
   // has received the flush.
   virtual uint64_t GenerateFenceSyncRelease() = 0;
@@ skipping 11 matching lines @@
   // be enqueued first so does not need to be flushed.
   virtual bool CanWaitUnverifiedSyncToken(const SyncToken* sync_token) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuControl);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GPU_CONTROL_H_