Enable TabManager on Linux

chrome/common/chrome_features.cc

Index: chrome/common/chrome_features.cc
diff --git a/chrome/common/chrome_features.cc b/chrome/common/chrome_features.cc
index 6a62d3717ddb389ef4565c30f6e71f74b7a569b9..fba1459865b9c2d8735df938f3d93adf7c0428fe 100644
--- a/chrome/common/chrome_features.cc
+++ b/chrome/common/chrome_features.cc
@@ -8,11 +8,11 @@ namespace features {
 
 // All features in alphabetical order.
 
-#if defined(OS_WIN) || defined(OS_MACOSX)
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
 // 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)
+#endif  // defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
 
 // Enables Expect CT reporting, which sends reports for opted-in sites
 // that don't serve sufficient Certificate Transparency information.