Enable use_once_callback for //content/common/*.mojom

content/browser/leveldb_wrapper_impl.h

Index: content/browser/leveldb_wrapper_impl.h
diff --git a/content/browser/leveldb_wrapper_impl.h b/content/browser/leveldb_wrapper_impl.h
index 3b4adba38a45f398c33fd758ce35349af0f3815f..9a59a64beeb451f720e2df07057894d2f0d962b1 100644
--- a/content/browser/leveldb_wrapper_impl.h
+++ b/content/browser/leveldb_wrapper_impl.h
@@ -83,17 +83,16 @@ class CONTENT_EXPORT LevelDBWrapperImpl : public mojom::LevelDBWrapper {
   void Put(const std::vector<uint8_t>& key,
            const std::vector<uint8_t>& value,
            const std::string& source,
-           const PutCallback& callback) override;
+           PutCallback callback) override;
   void Delete(const std::vector<uint8_t>& key,
               const std::string& source,
-              const DeleteCallback& callback) override;
+              DeleteCallback callback) override;
   void DeleteAll(const std::string& source,
-                 const DeleteAllCallback& callback) override;
-  void Get(const std::vector<uint8_t>& key,
-           const GetCallback& callback) override;
+                 DeleteAllCallback callback) override;
+  void Get(const std::vector<uint8_t>& key, GetCallback callback) override;
   void GetAll(
       mojom::LevelDBWrapperGetAllCallbackAssociatedPtrInfo complete_callback,
-      const GetAllCallback& callback) override;
+      GetAllCallback callback) override;
 
  private:
   // Used to rate limit commits.