Allow for pausing background tabs on desktop via about:flags.

chrome/browser/flag_descriptions.cc

Index: chrome/browser/flag_descriptions.cc
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 01081dfa3c51b068687e20163c994d3edb4367d1..42ab816c02080d4f4f5c793570e92c1565d1daa5 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -2721,6 +2721,10 @@ const char kOmniboxEntitySuggestionsName[] = "Omnibox entity suggestions";
 const char kOmniboxEntitySuggestionsDescription[] =
     "Enable receiving entity suggestions in Omnibox.";
 
+const char kPauseBackgroundTabsName[] = "Pause background tabs";
+const char kPauseBackgroundTabsDescription[] =
+    "Pause timers in background tabs after 5 minutes on desktop.";
+
 #endif  // defined(OS_CHROMEOS) || defined(OS_LINUX) || defined(OS_MACOSX) ||
         // defined(OS_WIN)