Removed CRWWebDelagate callbacks for load cancellation.

ios/chrome/browser/tabs/tab.mm

Index: ios/chrome/browser/tabs/tab.mm
diff --git a/ios/chrome/browser/tabs/tab.mm b/ios/chrome/browser/tabs/tab.mm
index 7301b09ff9e1243b9b10fcc3ad6cbc3d18c7e164..6baeb0de06d4a48436ba35f624f577b9b051851b 100644
--- a/ios/chrome/browser/tabs/tab.mm
+++ b/ios/chrome/browser/tabs/tab.mm
@@ -1666,11 +1666,6 @@ void TabInfoBarObserver::OnInfoBarReplaced(infobars::InfoBar* old_infobar,
                     object:self];
 }
 
-- (void)webCancelStartLoadingRequest {

[Eugene But (OOO till 7-30), 2017/03/10 23:43:00]

webStateDidStopLoading: is also called when provisional navigation is cancelled,
so this method can be removed.

-  DCHECK(self.webController.loadPhase == web::PAGE_LOADED);
-  [parentTabModel_ notifyTabChanged:self];
-}
-
 - (void)webState:(web::WebState*)webState
     didCommitNavigationWithDetails:(const web::LoadCommittedDetails&)details {
   DCHECK([self navigationManager]);
@@ -1801,8 +1796,9 @@ void TabInfoBarObserver::OnInfoBarReplaced(infobars::InfoBar* old_infobar,
   [parentTabModel_ notifyTabChanged:self];
 }
 
-- (void)webLoadCancelled:(const GURL&)url {
-  // When a load is cancelled, this is the maximum that a page will ever load.
+- (void)webStateDidStopLoading:(web::WebState*)webState {
+  // This is the maximum that a page will ever load and it is safe to allow
+  // fullscreen mode.
   [fullScreenController_ enableFullScreen];
   [parentTabModel_ notifyTabChanged:self];
 }