Add an API around SessionStorageNamespace. This is just an empty API, what matters to embedders is that they can influence this object's lifetime.

BUG=98716
Review URL: https://chromiumcodereview.appspot.com/9447039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@123389 0039d316-1c4b-4281-b951-d872f2087c98
35 files changed