Implement the ability to obliterate a storage partition from disk.

content/public/browser/storage_partition.h

Index: content/public/browser/storage_partition.h
diff --git a/content/public/browser/storage_partition.h b/content/public/browser/storage_partition.h
index a06a311219768672d7623c300867006093f04bed..2a905d90a7f1596eddb3a92e39e1e27273d9b6f6 100644
--- a/content/public/browser/storage_partition.h
+++ b/content/public/browser/storage_partition.h
@@ -68,6 +68,10 @@ class StoragePartition {
       const GURL& storage_origin,
       net::URLRequestContextGetter* request_context_getter) = 0;
 
+  // Similar to AsyncClearDataForOrigin(), but deletes all data out of the
+  // StoragePartition rather than just the data related to this origin.
+  virtual void AsyncClearAllData() = 0;
+
  protected:
   virtual ~StoragePartition() {}
 };