Rename StorageManager messages to refer to the StorageMap instead of the StorageArea
https://bugs.webkit.org/show_bug.cgi?id=114401

Reviewed by Ryosuke Niwa.

* UIProcess/Storage/StorageManager.cpp:
(WebKit::StorageManager::createStorageMap):
(WebKit::StorageManager::destroyStorageMap):
(WebKit::StorageManager::setItem):
* UIProcess/Storage/StorageManager.h:
* UIProcess/Storage/StorageManager.messages.in:
* WebProcess/Storage/StorageAreaImpl.cpp:
(WebKit::StorageAreaImpl::StorageAreaImpl):
(WebKit::StorageAreaImpl::~StorageAreaImpl):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148160 268f45cc-cd09-0410-ab3c-d52691b4dbfc