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

content/browser/storage_partition_impl_map.h

Index: content/browser/storage_partition_impl_map.h
diff --git a/content/browser/storage_partition_impl_map.h b/content/browser/storage_partition_impl_map.h
index 5c25e027f21edbcd66e51b511ced567293cb8180..3c875575988c2966cd2df7c80ceb5e0ac0cbffeb 100644
--- a/content/browser/storage_partition_impl_map.h
+++ b/content/browser/storage_partition_impl_map.h
@@ -10,6 +10,7 @@
 
 #include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
+#include "base/hash_tables.h"
 #include "base/supports_user_data.h"
 #include "content/browser/storage_partition_impl.h"
 #include "content/public/browser/browser_context.h"
@@ -34,7 +35,16 @@ class StoragePartitionImplMap : public base::SupportsUserData::Data {
 
   // Starts an asynchronous best-effort attempt to delete all on-disk storage
   // related to |site|, avoiding any directories that are known to be in use.
-  void AsyncObliterate(const GURL& site);
+  //
+  // |on_gc_required| is called if the AsyncObliterate() call was unable to
+  // fully clean the on-disk storage requiring a call to GarbageCollect() on
+  // the next browser start.
+  void AsyncObliterate(const GURL& site, const base::Closure& on_gc_required);
+
+  // Examines the on disk storage and removes any entires that are not listed in
+  // the active_paths, or in use by current entires in the storage partition.
+  void GarbageCollect(scoped_ptr<base::hash_set<FilePath> > active_paths,
+                      const base::Closure& done);
 
   void ForEach(const BrowserContext::StoragePartitionCallback& callback);