Clean up handling of invalid HWID when running ChromeOS in VMs

chromeos/system/fake_statistics_provider.h

Index: chromeos/system/fake_statistics_provider.h
diff --git a/chromeos/system/fake_statistics_provider.h b/chromeos/system/fake_statistics_provider.h
index d7f1c35be963c1977216b2b340c38e0fd6c0563b..78c540cfa616bea67d030ffe7ed1094cc1cbca2d 100644
--- a/chromeos/system/fake_statistics_provider.h
+++ b/chromeos/system/fake_statistics_provider.h
@@ -28,6 +28,7 @@ class FakeStatisticsProvider : public StatisticsProvider {
                            std::string* result) override;
   bool GetMachineFlag(const std::string& name, bool* result) override;
   void Shutdown() override;
+  bool IsRunningOnVm() override;
 
   void SetMachineStatistic(const std::string& key, const std::string& value);
   void ClearMachineStatistic(const std::string& key);