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

components/mus/gles2/command_buffer_impl.cc

 // 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.
 
 #include "components/mus/gles2/command_buffer_impl.h"
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "components/mus/gles2/command_buffer_driver.h"
@@ skipping 142 matching lines @@
   binding_->set_connection_error_handler([this]() { OnConnectionError(); });
 }
 
 void CommandBufferImpl::InitializeOnGpuThread(
     mojom::CommandBufferLostContextObserverPtr loss_observer,
     mojo::ScopedSharedBufferHandle shared_state,
     mojo::Array<int32_t> attribs,
     const base::Callback<void(mojom::CommandBufferInfoPtr)>& callback) {
   DCHECK(!driver_);
   driver_.reset(new CommandBufferDriver(
-      gpu::CommandBufferNamespace::MOJO, ++g_next_command_buffer_id,
+      gpu::CommandBufferNamespace::MOJO,
+      gpu::CommandBufferId::FromUnsafeValue(++g_next_command_buffer_id),
       gfx::kNullAcceleratedWidget, gpu_state_));
   driver_->set_client(make_scoped_ptr(new CommandBufferDriverClientImpl(this)));
   loss_observer_ = mojo::MakeProxy(loss_observer.PassInterface());
   bool result =
       driver_->Initialize(std::move(shared_state), std::move(attribs));
   mojom::CommandBufferInfoPtr info;
   if (result) {
     info = mojom::CommandBufferInfo::New();
     info->command_buffer_namespace = driver_->GetNamespaceID();
-    info->command_buffer_id = driver_->GetCommandBufferID();
+    info->command_buffer_id = driver_->GetCommandBufferID().GetUnsafeValue();
     info->capabilities =
         mojom::GpuCapabilities::From(driver_->GetCapabilities());
   }
   gpu_state_->control_task_runner()->PostTask(
       FROM_HERE, base::Bind(callback, base::Passed(&info)));
 }
 
 bool CommandBufferImpl::SetGetBufferOnGpuThread(int32_t buffer) {
   DCHECK(driver_->IsScheduled());
   driver_->SetGetBuffer(buffer);
@@ skipping 71 matching lines @@
       driver_.get(), base::Bind(&CommandBufferImpl::DeleteOnGpuThread,
                                 base::Unretained(this)));
 }
 
 bool CommandBufferImpl::DeleteOnGpuThread() {
   delete this;
   return true;
 }
 
 }  // namespace mus