Add BackgroundModeOptimizer that can restart the browser

chrome/common/chrome_features.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/chrome_features.h"
 
 namespace features {
 
 // All features in alphabetical order.
 
 #if defined(OS_CHROMEOS)
 // Whether to handle low memory kill of ARC apps by Chrome.
 const base::Feature kArcMemoryManagement{
     "ArcMemoryManagement", base::FEATURE_ENABLED_BY_DEFAULT};
 #endif  // defined(OS_CHROMEOS)
 
 #if defined(OS_WIN) || defined(OS_MACOSX)
 // Enables automatic tab discarding, when the system is in low memory state.
 const base::Feature kAutomaticTabDiscarding{"AutomaticTabDiscarding",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // defined(OS_WIN) || defined(OS_MACOSX)
 
+#if defined(OS_WIN) || defined(OS_LINUX)
+// Enables the Restart background mode optimization. When all Chrome UI is
+// closed and it goes in the background, allows to restart the browser to
+// discard memory.
+const base::Feature kBackgroundModeAllowRestart{
+    "BackgroundModeAllowRestart", base::FEATURE_DISABLED_BY_DEFAULT};
+#endif  // defined(OS_WIN) || defined(OS_LINUX)
+
 // Experiment to disable small cross-origin content. (http://crbug.com/608886)
 const base::Feature kBlockSmallContent{"BlockSmallPluginContent",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Fixes for browser hang bugs are deployed in a field trial in order to measure
 // their impact. See crbug.com/478209.
 const base::Feature kBrowserHangFixesExperiment{
     "BrowserHangFixesExperiment", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Enables Expect CT reporting, which sends reports for opted-in sites
@@ skipping 62 matching lines @@
                                           base::FEATURE_DISABLED_BY_DEFAULT};
 #endif
 
 #if defined(OS_CHROMEOS)
 // Enables or disables the opt-in IME menu in the language settings page.
 const base::Feature kOptInImeMenu{"OptInImeMenu",
                                   base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace features