Extract a base class from CommandLinePrefStore

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index bcf860a7b727fffef7001c70b408863eaa104dbc..8ef721ef7183f6308103dd31df363451c74fc982 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -841,12 +841,12 @@ split_static_library("browser") {
     "predictors/resource_prefetcher_manager.h",
     "prefs/browser_prefs.cc",
     "prefs/browser_prefs.h",
+    "prefs/chrome_command_line_pref_store.cc",
+    "prefs/chrome_command_line_pref_store.h",
     "prefs/chrome_pref_model_associator_client.cc",
     "prefs/chrome_pref_model_associator_client.h",
     "prefs/chrome_pref_service_factory.cc",
     "prefs/chrome_pref_service_factory.h",
-    "prefs/command_line_pref_store.cc",
-    "prefs/command_line_pref_store.h",
     "prefs/incognito_mode_prefs.cc",
     "prefs/incognito_mode_prefs.h",
     "prefs/origin_trial_prefs.cc",
@@ -1355,6 +1355,7 @@ split_static_library("browser") {
     "//components/policy:generated",
     "//components/policy/core/browser",
     "//components/policy/proto",
+    "//components/prefs:prefs",
     "//components/previews/core",
     "//components/profile_metrics",
     "//components/proxy_config",