Add a preference to clear plugin data on browser shutdown.

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 3e84d5388f74848fb1969e118de585600dd3298a..44faf37b145b1f6813f6c6c82bf503b4b4abf8ce 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -558,6 +558,11 @@ const char kBlockNonsandboxedPlugins[] = "profile.block_nonsandboxed_plugins";
 // storage, etc..) should be deleted on exit.
 const char kClearSiteDataOnExit[] = "profile.clear_site_data_on_exit";
 
+// Boolean that is true when plug-in locally stored data ("Flash cookies")
+// should be deleted on exit.
+const char kClearPluginLSODataOnExit[] =
+    "profile.clear_plugin_lso_data_on_exit";
+
 // Double that indicates the default zoom level.
 const char kDefaultZoomLevel[] = "profile.default_zoom_level";