Add a preference to clear Flash LSO data in the Clear Browsing Data dialog.

chrome/browser/browser_shutdown.cc

Index: chrome/browser/browser_shutdown.cc
diff --git a/chrome/browser/browser_shutdown.cc b/chrome/browser/browser_shutdown.cc
index e136ef85130298f0ce961f065cf0e4eccf6e1113..87728fdb2a32fb619ac27f052e2baaeb3d512692 100644
--- a/chrome/browser/browser_shutdown.cc
+++ b/chrome/browser/browser_shutdown.cc
@@ -26,8 +26,10 @@
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/jankometer.h"
 #include "chrome/browser/metrics/metrics_service.h"
+#include "chrome/browser/plugin_data_remover.h"
 #include "chrome/browser/plugin_process_host.h"
 #include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profile_manager.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/renderer_host/render_widget_host.h"
@@ -115,14 +117,6 @@ void Shutdown() {
   // shutdown.
   base::ThreadRestrictions::SetIOAllowed(true);
 
-  // Unload plugins. This needs to happen on the IO thread.
-  BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        NewRunnableFunction(&ChromePluginLib::UnloadAllPlugins));
-
-  // Shutdown all IPC channels to service processes.
-  ServiceProcessControlManager::instance()->Shutdown();
-
   // WARNING: During logoff/shutdown (WM_ENDSESSION) we may not have enough
   // time to get here. If you have something that *must* happen on end session,
   // consider putting it in BrowserProcessImpl::EndSession.
@@ -131,9 +125,29 @@ void Shutdown() {
   // Notifies we are going away.
   g_browser_process->shutdown_event()->Signal();
 
-  PrefService* prefs = g_browser_process->local_state();
+  PrefService* local_state = g_browser_process->local_state();
+
+  // Unload plugins. This needs to happen on the IO thread.
+  BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        NewRunnableFunction(&ChromePluginLib::UnloadAllPlugins));
+
+  Profile* profile = ProfileManager::GetDefaultProfile();
+  if (profile) {
+    // Store the profile path for clearing local state data on exit.
+    PrefService* prefs = profile->GetPrefs();
+    if (prefs->GetBoolean(prefs::kClearPluginLSODataOnExit) &&
+        local_state->GetBoolean(prefs::kClearPluginLSODataEnabled)) {
+      PluginDataRemover remover;
+      remover.StartRemoving(base::Time(), new MessageLoop::QuitTask());

[jam, 2010/11/29 17:14:08]

I have a big concern about blocking our shutdown to wait on creating a Flash
process.  That could be pretty slow for various reasons (i.e. system is
overloaded, Flash loads slowly).  If a user is waiting to restart Chrome again
(say because they shutdown Chrome for an auto-update), and try to start Chrome
manually while this is happening, it won't work.  They might shutdown Chrome
processes manually which would be unfortunate as it could lead to profile
corruption.

Running a nested message loop also seems kind of scary, it's really hard to
predict the side-effects of reentrancy at this point in shutdown.

If the user has the kClearPluginLSODataOnExit pref set, why not just call
Flash's ClearLSO function each time before we shutdown the Flash process?  That
way there's no slowing down of shutdown, which is critical, and it would avoid
any race conditions that you mention.

+      MessageLoop::current()->Run();
+    }
+  }
+
+  // Shutdown all IPC channels to service processes.
+  ServiceProcessControlManager::instance()->Shutdown();
 
-  chrome_browser_net::SavePredictorStateForNextStartupAndTrim(prefs);
+  chrome_browser_net::SavePredictorStateForNextStartupAndTrim(local_state);
 
   MetricsService* metrics = g_browser_process->metrics_service();
   if (metrics) {
@@ -144,21 +158,22 @@ void Shutdown() {
   if (shutdown_type_ > NOT_VALID && shutdown_num_processes_ > 0) {
     // Record the shutdown info so that we can put it into a histogram at next
     // startup.
-    prefs->SetInteger(prefs::kShutdownType, shutdown_type_);
-    prefs->SetInteger(prefs::kShutdownNumProcesses, shutdown_num_processes_);
-    prefs->SetInteger(prefs::kShutdownNumProcessesSlow,
-                      shutdown_num_processes_slow_);
+    local_state->SetInteger(prefs::kShutdownType, shutdown_type_);
+    local_state->SetInteger(prefs::kShutdownNumProcesses,
+                            shutdown_num_processes_);
+    local_state->SetInteger(prefs::kShutdownNumProcessesSlow,
+                            shutdown_num_processes_slow_);
   }
 
   // Check local state for the restart flag so we can restart the session below.
   bool restart_last_session = false;
-  if (prefs->HasPrefPath(prefs::kRestartLastSessionOnShutdown)) {
+  if (local_state->HasPrefPath(prefs::kRestartLastSessionOnShutdown)) {
     restart_last_session =
-        prefs->GetBoolean(prefs::kRestartLastSessionOnShutdown);
-    prefs->ClearPref(prefs::kRestartLastSessionOnShutdown);
+        local_state->GetBoolean(prefs::kRestartLastSessionOnShutdown);
+    local_state->ClearPref(prefs::kRestartLastSessionOnShutdown);
   }
 
-  prefs->SavePersistentPrefs();
+  local_state->SavePersistentPrefs();
 
 #if defined(OS_WIN) && defined(GOOGLE_CHROME_BUILD)
   // Cleanup any statics created by RLZ. Must be done before NotificationService