Add KVO compliant title property to CWVWebView.

ios/web_view/internal/cwv_web_view.mm

 // Copyright 2014 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_view/public/cwv_web_view.h"
 
 #include <memory>
 #include <utility>
 
 #import "base/ios/weak_nsobject.h"
@@ skipping 61 matching lines @@
       _javaScriptDialogPresenter;
 }
 
 // Redefine the property as readwrite.
 @property(nonatomic, copy) CWVWebViewConfiguration* configuration;
 // Redefine these properties as readwrite to define setters, which send KVO
 // notifications.
 @property(nonatomic, readwrite) double estimatedProgress;
 @property(nonatomic, readwrite) BOOL canGoBack;
 @property(nonatomic, readwrite) BOOL canGoForward;
+@property(nonatomic, readwrite, copy) NSString* title;
 
 // Updates the availability of the back/forward navigation properties exposed
 // through |canGoBack| and |canGoForward|.
 - (void)updateNavigationAvailability;
 
 @end
 
 static NSString* gUserAgentProduct = nil;
 
 @implementation CWVWebView
 
 @synthesize canGoBack = _canGoBack;
 @synthesize canGoForward = _canGoForward;
 @synthesize configuration = _configuration;
 @synthesize estimatedProgress = _estimatedProgress;
 @synthesize navigationDelegate = _navigationDelegate;
+@synthesize title = _title;
 @synthesize translationController = _translationController;
 @synthesize UIDelegate = _UIDelegate;
 @synthesize scrollView = _scrollView;
 
 + (NSString*)userAgentProduct {
   return gUserAgentProduct;
 }
 
 + (void)setUserAgentProduct:(NSString*)product {
   gUserAgentProduct = [product copy];
@@ skipping 30 matching lines @@
 }
 
 - (NSURL*)visibleURL {
   return net::NSURLWithGURL(_webState->GetVisibleURL());
 }
 
 - (NSURL*)lastCommittedURL {
   return net::NSURLWithGURL(_webState->GetLastCommittedURL());
 }
 
-- (NSString*)title {
-  return base::SysUTF16ToNSString(_webState->GetTitle());
-}
-
 - (void)goBack {
   if (_webState->GetNavigationManager())
     _webState->GetNavigationManager()->GoBack();
 }
 
 - (void)goForward {
   if (_webState->GetNavigationManager())
     _webState->GetNavigationManager()->GoForward();
 }
 
@@ skipping 62 matching lines @@
   if ([_navigationDelegate respondsToSelector:selector]) {
     [_navigationDelegate webView:self didLoadPageWithSuccess:success];
   }
 }
 
 - (void)webState:(web::WebState*)webState
     didChangeLoadingProgress:(double)progress {
   self.estimatedProgress = progress;
 }
 
+- (void)webStateDidChangeTitle:(web::WebState*)webState {
+  self.title = base::SysUTF16ToNSString(_webState->GetTitle());
+}
+
 - (void)renderProcessGoneForWebState:(web::WebState*)webState {
   SEL selector = @selector(webViewWebContentProcessDidTerminate:);
   if ([_navigationDelegate respondsToSelector:selector]) {
     [_navigationDelegate webViewWebContentProcessDidTerminate:self];
   }
 }
 
 - (BOOL)webState:(web::WebState*)webState
     handleContextMenu:(const web::ContextMenuParams&)params {
   SEL selector = @selector(webView:runContextMenuWithTitle:forHTMLElement:inView
@@ skipping 132 matching lines @@
   [self addSubview:subview];
 }
 
 - (void)updateNavigationAvailability {
   self.canGoBack = _webState && _webState->GetNavigationManager()->CanGoBack();
   self.canGoForward =
       _webState && _webState->GetNavigationManager()->CanGoForward();
 }
 
 @end