Make a VoiceOver announcement when a page has loaded.

ios/chrome/browser/ui/toolbar/web_toolbar_controller.mm

 // Copyright 2012 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/chrome/browser/ui/toolbar/web_toolbar_controller.h"
 
 #import <CoreLocation/CoreLocation.h>
 #include <QuartzCore/QuartzCore.h>
 
 #include <stdint.h>
@@ skipping 1613 matching lines @@
       // Calling -completeAndHide while a prerender animation is in progress
       // will result in hiding the progress bar before the animation is
       // complete.
       [_determinateProgressView setProgress:1
                                    animated:YES
                                  completion:^(BOOL finished) {
                                    [_determinateProgressView setHidden:YES
                                                               animated:YES
                                                             completion:nil];
                                  }];
+      UIAccessibilityPostNotification(
+          UIAccessibilityAnnouncementNotification,
+          l10n_util::GetNSString(
+              IDS_IOS_PAGE_LOADED_ACCESSIBILITY_ANNOUNCEMENT));
     }
     CGFloat delay = _unitTesting ? 0 : kLoadCompleteHideProgressBarDelay;
     [self performSelector:@selector(hideProgressBarAndTakeSnapshot)
                withObject:nil
                afterDelay:delay];
   }
 }
 
 - (void)hideProgressBarAndTakeSnapshot {
   // The UI may have been torn down while this selector was queued.  If
@@ skipping 920 matching lines @@
 
 - (BOOL)isPrerenderAnimationRunning {
   return _prerenderAnimating;
 }
 
 - (OmniboxTextFieldIOS*)omnibox {
   return _omniBox.get();
 }
 
 @end