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

components/mus/gles2/command_buffer_impl.cc

Index: components/mus/gles2/command_buffer_impl.cc
diff --git a/components/mus/gles2/command_buffer_impl.cc b/components/mus/gles2/command_buffer_impl.cc
index aa8fa3b10760735a3246849d21a6485f896afcb9..3fa28f2192c42f097789c8cc7d7958f33d1de025 100644
--- a/components/mus/gles2/command_buffer_impl.cc
+++ b/components/mus/gles2/command_buffer_impl.cc
@@ -160,7 +160,8 @@ void CommandBufferImpl::InitializeOnGpuThread(
     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());
@@ -170,7 +171,7 @@ void CommandBufferImpl::InitializeOnGpuThread(
   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());
   }