Switch to direct use of OwnerSettingsServiceChromeOS::Set() in tests.

chrome/browser/chromeos/settings/device_settings_provider.h

Index: chrome/browser/chromeos/settings/device_settings_provider.h
diff --git a/chrome/browser/chromeos/settings/device_settings_provider.h b/chrome/browser/chromeos/settings/device_settings_provider.h
index 4705e6176feefe80faa47e6bff9697e0eeb56199..b864748b52e1ab2bd044f7352d8e472c0dc15208 100644
--- a/chrome/browser/chromeos/settings/device_settings_provider.h
+++ b/chrome/browser/chromeos/settings/device_settings_provider.h
@@ -53,6 +53,8 @@ class DeviceSettingsProvider
   TrustedStatus PrepareTrustedValues(const base::Closure& callback) override;
   bool HandlesSetting(const std::string& path) const override;
 
+  void set_trusted_for_test(bool trusted) { trusted_for_test_ = trusted; }
+
  private:
   // CrosSettingsProvider implementation:
   void DoSet(const std::string& path, const base::Value& value) override;
@@ -123,6 +125,9 @@ class DeviceSettingsProvider
   TrustedStatus trusted_status_;
   DeviceSettingsService::OwnershipStatus ownership_status_;
 
+  // Allows to skip waiting for the trusted values in unit tests.
+  bool trusted_for_test_;
+
   // The device settings as currently reported through the
   // CrosSettingsProvider interface. This may be different from the
   // actual current device settings (which can be obtained from