Add Get/SetDisplayLayout to chrome.system.display extension API

chrome/browser/extensions/display_info_provider_chromeos.h

Index: chrome/browser/extensions/display_info_provider_chromeos.h
diff --git a/chrome/browser/extensions/display_info_provider_chromeos.h b/chrome/browser/extensions/display_info_provider_chromeos.h
index 142d8da4a571306a68a152d1d410b89793fc6860..d0a173ddf39cc57d677c5c4f5be00d319a965008 100644
--- a/chrome/browser/extensions/display_info_provider_chromeos.h
+++ b/chrome/browser/extensions/display_info_provider_chromeos.h
@@ -26,11 +26,13 @@ class DisplayInfoProviderChromeOS : public DisplayInfoProvider {
   bool SetInfo(const std::string& display_id,
                const api::system_display::DisplayProperties& info,
                std::string* error) override;
+  bool SetDisplayLayout(const DisplayLayoutList& layouts) override;
   void UpdateDisplayUnitInfoForPlatform(
       const display::Display& display,
       api::system_display::DisplayUnitInfo* unit) override;
   void EnableUnifiedDesktop(bool enable) override;
   DisplayUnitInfoList GetAllDisplaysInfo() override;
+  DisplayLayoutList GetDisplayLayout() override;
   bool OverscanCalibrationStart(const std::string& id) override;
   bool OverscanCalibrationAdjust(
       const std::string& id,