[Mac] Transition MiniBrowser to the Cocoa API: load delegate

[Mac] Transition MiniBrowser to the Cocoa API: load delegate
https://bugs.webkit.org/show_bug.cgi?id=125334

Reviewed by Darin Adler.

* MiniBrowser/mac/WK2BrowserWindowController.m:
(-[WK2BrowserWindowController dealloc]): Nil out the load delegate and stop observing the
title property.
(-[WK2BrowserWindowController isPaginated]): Changed to use Cocoa SPI.
(-[WK2BrowserWindowController togglePaginationMode:]): Ditto.
(-[WK2BrowserWindowController observeValueForKeyPath:ofObject:change:context:]): Update the
window title with the title property changes.
(-[WK2BrowserWindowController awakeFromNib]): Start observing the title property. Changed to
set the load delegate instead of the load client.
(-[WK2BrowserWindowController updateTextFieldFromURL:]): Changed to use Cocoa types.
(-[WK2BrowserWindowController updateProvisionalURL]): Removed frame parameter.
(-[WK2BrowserWindowController updateCommittedURL]): Ditto.
(-[WK2BrowserWindowController browsingContextControllerDidStartProvisionalLoad:]):
Implemented this load delegate method.
(-[WK2BrowserWindowController browsingContextControllerDidReceiveServerRedirectForProvisionalLoad:]):
Ditto.
(-[WK2BrowserWindowController browsingContextController:didFailProvisionalLoadWithError:]): Ditto.
(-[WK2BrowserWindowController browsingContextControllerDidCommitLoad:]): Ditto.
(-[WK2BrowserWindowController browsingContextControllerDidFinishLoad:]): Ditto.
(-[WK2BrowserWindowController browsingContextController:didFailLoadWithError:]): Ditto.
(-[WK2BrowserWindowController browsingContextControllerDidChangeBackForwardList:addedItem:removedItems:]):
Ditto.
(-[WK2BrowserWindowController browsingContextController:canAuthenticateAgainstProtectionSpace:]):
Ditto.
(-[WK2BrowserWindowController browsingContextController:didReceiveAuthenticationChallenge:]): Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@160231 268f45cc-cd09-0410-ab3c-d52691b4dbfc