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

components/mus/gles2/command_buffer_local.cc

 // Copyright 2015 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 "components/mus/gles2/command_buffer_local.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/memory/shared_memory.h"
 #include "base/synchronization/waitable_event.h"
@@ skipping 305 matching lines @@
 
 void CommandBufferLocal::EnsureWorkVisible() {
   // This is only relevant for out-of-process command buffers.
 }
 
 gpu::CommandBufferNamespace CommandBufferLocal::GetNamespaceID() const {
   DCHECK(CalledOnValidThread());
   return gpu::CommandBufferNamespace::MOJO_LOCAL;
 }
 
-uint64_t CommandBufferLocal::GetCommandBufferID() const {
+gpu::CommandBufferId CommandBufferLocal::GetCommandBufferID() const {
   DCHECK(CalledOnValidThread());
   return driver_->GetCommandBufferID();
 }
 
 int32_t CommandBufferLocal::GetExtraCommandBufferData() const {
   DCHECK(CalledOnValidThread());
   return 0;
 }
 
 uint64_t CommandBufferLocal::GenerateFenceSyncRelease() {
@@ skipping 77 matching lines @@
       base::Bind(&CommandBufferLocal::MakeProgressOnGpuThread,
                  base::Unretained(this), base::Unretained(&event),
                  base::Unretained(&state)));
   event.Wait();
   if (state.generation - last_state_.generation < 0x80000000U)
     last_state_ = state;
 }
 
 void CommandBufferLocal::InitializeOnGpuThread(base::WaitableEvent* event,
                                                bool* result) {
-  driver_.reset(new CommandBufferDriver(gpu::CommandBufferNamespace::MOJO_LOCAL,
-                                        ++g_next_command_buffer_id, widget_,
-                                        gpu_state_));
+  driver_.reset(new CommandBufferDriver(
+      gpu::CommandBufferNamespace::MOJO_LOCAL,
+      gpu::CommandBufferId::FromUnsafeValue(++g_next_command_buffer_id),
+      widget_, gpu_state_));
   const size_t kSharedStateSize = sizeof(gpu::CommandBufferSharedState);
   void* memory = nullptr;
   mojo::ScopedSharedBufferHandle duped;
   *result = CreateMapAndDupSharedBuffer(kSharedStateSize, &memory,
                                         &shared_state_handle_, &duped);
 
   if (!*result) {
     event->Signal();
     return;
   }
@@ skipping 88 matching lines @@
     client_->DidLoseContext();
 }
 
 void CommandBufferLocal::UpdateVSyncParametersOnClientThread(int64_t timebase,
                                                              int64_t interval) {
   if (client_)
     client_->UpdateVSyncParameters(timebase, interval);
 }
 
 }  // namespace mus