Fixed typo in InterstitialDismissed method name.

ios/web/web_state/web_state_observer_bridge.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/public/web_state/web_state_observer_bridge.h"
 
 namespace web {
 
 WebStateObserverBridge::WebStateObserverBridge(web::WebState* webState,
                                                id<CRWWebStateObserver> observer)
@@ skipping 43 matching lines @@
         success = YES;
         break;
       case PageLoadCompletionStatus::FAILURE:
         success = NO;
         break;
     }
     [observer_ webState:web_state() didLoadPageWithSuccess:success];
   }
 }
 
-void WebStateObserverBridge::InsterstitialDismissed() {
+void WebStateObserverBridge::InterstitialDismissed() {
   SEL selector = @selector(webStateDidDismissInterstitial:);
   if ([observer_ respondsToSelector:selector])
     [observer_ webStateDidDismissInterstitial:web_state()];
 }
 
 void WebStateObserverBridge::UrlHashChanged() {
   SEL selector = @selector(webStateDidChangeURLHash:);
   if ([observer_ respondsToSelector:selector])
     [observer_ webStateDidChangeURLHash:web_state()];
 }
@@ skipping 58 matching lines @@
 void WebStateObserverBridge::WebStateDestroyed() {
   SEL selector = @selector(webStateDestroyed:);
   if ([observer_ respondsToSelector:selector]) {
     // |webStateDestroyed:| may delete |this|, so don't expect |this| to be
     // valid afterwards.
     [observer_ webStateDestroyed:web_state()];
   }
 }
 
 }  // namespace web