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

extensions/browser/api/system_display/display_info_provider.cc

Index: extensions/browser/api/system_display/display_info_provider.cc
diff --git a/extensions/browser/api/system_display/display_info_provider.cc b/extensions/browser/api/system_display/display_info_provider.cc
index 914cd8b5619cbd5c260b559288a5474dbffc2d63..64d5161c31f886a6d500424bee90bd4d6deb5c86 100644
--- a/extensions/browser/api/system_display/display_info_provider.cc
+++ b/extensions/browser/api/system_display/display_info_provider.cc
@@ -73,9 +73,15 @@ api::system_display::DisplayUnitInfo DisplayInfoProvider::CreateDisplayUnitInfo(
   return unit;
 }
 
+bool DisplayInfoProvider::SetDisplayLayout(const DisplayLayoutList& layout) {
+  NOTREACHED();  // Implemented on Chrome OS only in override.
+  return false;
+}
+
 void DisplayInfoProvider::EnableUnifiedDesktop(bool enable) {}
 
-DisplayUnitInfoList DisplayInfoProvider::GetAllDisplaysInfo() {
+DisplayInfoProvider::DisplayUnitInfoList
+DisplayInfoProvider::GetAllDisplaysInfo() {
   display::Screen* screen = display::Screen::GetScreen();
   int64_t primary_id = screen->GetPrimaryDisplay().id();
   std::vector<display::Display> displays = screen->GetAllDisplays();
@@ -89,6 +95,11 @@ DisplayUnitInfoList DisplayInfoProvider::GetAllDisplaysInfo() {
   return all_displays;
 }
 
+DisplayInfoProvider::DisplayLayoutList DisplayInfoProvider::GetDisplayLayout() {
+  NOTREACHED();  // Implemented on Chrome OS only in override.
+  return DisplayLayoutList();
+}
+
 bool DisplayInfoProvider::OverscanCalibrationStart(const std::string& id) {
   return false;
 }