Allow creation of CRWSessionStorage outside of serialisation API.
For recreating fake session during unit tests, allow creation of
CRWSessionStorage instance outside of the serialization code (this
required supporting null in AddSerializableUserData method).
Fix typos in serializable_user_data_manager_impl.mm, convert the
code to use base::MakeUnique<> and to pass std::unique_ptr<> to
base::SupportsUserData::SetUserData method.
BUG=None
Review-Url: https://codereview.chromium.org/2726713002
Cr-Commit-Position: refs/heads/master@{#454180}
2 files changed
