Garbage Collect the Storage directory on next profile start after an extension uninstall.

chrome/browser/extensions/extension_prefs.cc

Index: chrome/browser/extensions/extension_prefs.cc
diff --git a/chrome/browser/extensions/extension_prefs.cc b/chrome/browser/extensions/extension_prefs.cc
index a26f3ad4cd0992ead9258af17b7c3360f6b8181a..b63c4e6f28fd09bb87009fca331f0b4b2f8c63a1 100644
--- a/chrome/browser/extensions/extension_prefs.cc
+++ b/chrome/browser/extensions/extension_prefs.cc
@@ -1875,7 +1875,7 @@ bool ExtensionPrefs::GetSideloadWipeoutDone() const {
 }
 
 void ExtensionPrefs::SetSideloadWipeoutDone() {
-  return prefs_->SetBoolean(kSideloadWipeoutDone, true);
+  prefs_->SetBoolean(kSideloadWipeoutDone, true);
 }
 
 bool ExtensionPrefs::WasAppDraggedByUser(const std::string& extension_id) {
@@ -2254,6 +2254,14 @@ void ExtensionPrefs::Init(bool extensions_disabled) {
   content_settings_store_->AddObserver(this);
 }
 
+void ExtensionPrefs::SetNeedsStorageGarbageCollection(bool value) {
+  prefs_->SetBoolean(prefs::kExtensionStorageGarbageCollect, value);
+}
+
+bool ExtensionPrefs::NeedsStorageGarbageCollection() {
+  return prefs_->GetBoolean(prefs::kExtensionStorageGarbageCollect);
+}
+
 // static
 void ExtensionPrefs::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterDictionaryPref(kExtensionsPref, PrefService::UNSYNCABLE_PREF);
@@ -2277,6 +2285,11 @@ void ExtensionPrefs::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterStringPref(prefs::kExtensionBlacklistUpdateVersion,
                             "0",  // default value
                             PrefService::UNSYNCABLE_PREF);
+  // TODO(ajwong): Should this be syncable? What happens when you sync an
+  // extension uninstall?

[Charlie Reis, 2012/12/05 02:25:40]

I'm guessing it should not be syncable.  Each instance should decide for itself
when to set this dirty bit.  If you hear about an extension uninstall from sync,
won't that set your local dirty bit as usual?

[awong, 2012/12/08 01:45:23]

Agreed. Removed comment.

+  prefs->RegisterBooleanPref(prefs::kExtensionStorageGarbageCollect,
+                             false,  // default value
+                             PrefService::UNSYNCABLE_PREF);
   prefs->RegisterInt64Pref(prefs::kLastExtensionsUpdateCheck,
                            0,  // default value
                            PrefService::UNSYNCABLE_PREF);