Implement sidebar support for extension action popups

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 41ff0eb005806871f91f09ee3e6229541bdc6596..d9d5519abb892423d84d805b1d6cce986ad95684 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1517,6 +1517,8 @@ const char kDisablePluginFinder[] = "plugins.disable_plugin_finder";
 // Customized app page names that appear on the New Tab Page.
 const char kNtpAppPageNames[] = "ntp.app_page_names";
 
+const char kExtensionSidebarWidth[] = "extensions.sidebar.width";
+
 #if defined(OS_ANDROID)
 // Keeps track of currently open tabs collapsed state in the Other Devices menu.
 const char kNtpCollapsedCurrentlyOpenTabs[] = "ntp.collapsed_open_tabs";