Make cros_healthd CpuInfo field model_name optional

There are certain arm devices that do not populate the model name of the
CPU in sysfs. This change makes the model_name field optional to reflect
this.

Bug: chromium:1132875
Change-Id: I7f8c814bf77c22cc7f7ca6f482d37f46097a4335
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2436383Reviewed-by: Bailey Berro <baileyberro@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Oleh Lamzin <lamzin@google.com>
Commit-Queue: Trent Begin <tbegin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812172}

chrome/browser/chromeos/policy/status_collector/device_status_collector.cc

@@ -1057,7 +1057,8 @@ class DeviceStatusCollectorState : public StatusCollectorState {
 
             em::CpuInfo* const cpu_info_out =
                 response_params_.device_status->add_cpu_info();
-            cpu_info_out->set_model_name(physical_cpu->model_name);
+            if (physical_cpu->model_name)
+              cpu_info_out->set_model_name(physical_cpu->model_name.value());
             cpu_info_out->set_architecture(
                 static_cast<em::CpuInfo::Architecture>(cpu_info->architecture));
 

chromeos/components/diagnostics_ui/backend/system_data_provider.cc

@@ -44,7 +44,7 @@ void PopulateCpuInfo(const healthd::CpuInfo& cpu_info,
 
   // If there is more than one physical cpu on the device, use the name of the
   // first CPU.
-  out_system_info.cpu_model_name = physical_cpus[0]->model_name;
+  out_system_info.cpu_model_name = physical_cpus[0]->model_name.value_or("");
 }
 
 void PopulateVersionInfo(const healthd::SystemInfo& system_info,

chromeos/services/cros_healthd/public/mojom/cros_healthd_probe.mojom

@@ -290,8 +290,8 @@ struct CpuInfo {
 
 // Information related to a particular physical CPU.
 struct PhysicalCpuInfo {
-  // The CPU model name.
-  string model_name;
+  // The CPU model name, if available.
+  string? model_name;
   // Logical CPUs corresponding to this physical CPU.
   array<LogicalCpuInfo> logical_cpus;
 };