Implement the ability to obliterate a storage partition from disk.

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 9da35c304aa0e76f4c4e0bfd34322ee947973715..f9592daf16e957e51c490390632829ca1b374a6e 100644
--- a/content/browser/storage_partition_impl_map.h
+++ b/content/browser/storage_partition_impl_map.h
@@ -32,6 +32,11 @@ class StoragePartitionImplMap : public base::SupportsUserData::Data {
                             const std::string& partition_name,
                             bool in_memory);
 
+  // Starts an asynchronous best-effort attempt to delete all on-disk storage
+  // related to |site|, avoiding any directories that are in use by
+  // |partition_map|.
+  void AsyncObliterate(const GURL& site);
+
   void ForEach(const BrowserContext::StoragePartitionCallback& callback);
 
  private: