[ios] Use WebStateObserver to update url bar in ios_web_shell.

ios/web/shell/view_controller.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/shell/view_controller.h"
 
 #include <stdint.h>
 
 #include <utility>
 
 #include "base/mac/objc_property_releaser.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ios/net/cookies/cookie_store_ios.h"
 #import "ios/net/crn_http_protocol_handler.h"
 #import "ios/net/empty_nsurlcache.h"
 #import "ios/web/navigation/crw_session_controller.h"
 #import "ios/web/net/crw_url_verifying_protocol_handler.h"
 #include "ios/web/net/request_tracker_factory_impl.h"
 #import "ios/web/net/web_http_protocol_handler_delegate.h"
 #include "ios/web/public/referrer.h"
 #import "ios/web/public/web_controller_factory.h"
 #include "ios/web/public/web_state/web_state.h"
+#import "ios/web/public/web_state/web_state_observer_bridge.h"
 #include "ios/web/shell/shell_browser_state.h"
 #include "ios/web/web_state/ui/crw_web_controller.h"
 #include "ios/web/web_state/web_state_impl.h"
 #include "ui/base/page_transition_types.h"
 
 NSString* const kWebShellBackButtonAccessibilityLabel = @"Back";
 NSString* const kWebShellForwardButtonAccessibilityLabel = @"Forward";
 NSString* const kWebShellAddressFieldAccessibilityLabel = @"Address field";
 
 using web::NavigationManager;
 
-@interface ViewController ()<CRWWebUserInterfaceDelegate> {
+@interface ViewController ()<CRWWebStateObserver, CRWWebUserInterfaceDelegate> {
   web::BrowserState* _browserState;
   base::scoped_nsobject<CRWWebController> _webController;
   scoped_ptr<web::RequestTrackerFactoryImpl> _requestTrackerFactory;
   scoped_ptr<web::WebHTTPProtocolHandlerDelegate> _httpProtocolDelegate;
+  scoped_ptr<web::WebStateObserverBridge> _webStateObserver;
 
   base::mac::ObjCPropertyReleaser _propertyReleaser_ViewController;
 }
 @property(nonatomic, assign, readonly) web::WebState* webState;
 @property(nonatomic, readwrite, retain) UITextField* field;
 @end
 
 @implementation ViewController
 
 @synthesize field = _field;
@@ skipping 62 matching lines @@
   // Set up the network stack before creating the WebState.
   [self setUpNetworkStack];
 
   scoped_ptr<web::WebStateImpl> webState(new web::WebStateImpl(_browserState));
   webState->GetNavigationManagerImpl().InitializeSession(nil, nil, NO, 0);
   _webController.reset(web::CreateWebController(std::move(webState)));
   [_webController setDelegate:self];
   [_webController setUIDelegate:self];
   [_webController setWebUsageEnabled:YES];
 
+  _webStateObserver.reset(new web::WebStateObserverBridge(self.webState, self));
+
   UIView* view = self.webState->GetView();
   [view setFrame:[_containerView bounds]];
   [_containerView addSubview:view];
 
   NavigationManager::WebLoadParams params(GURL("https://dev.chromium.org/"));
   params.transition_type = ui::PAGE_TRANSITION_TYPED;
   [_webController loadWithParams:params];
 }
 
 - (web::WebState*)webState {
@@ skipping 119 matching lines @@
   if (newIndex >= [colors count]) {
     // TODO(rohitrao): Out of colors!  Consider prompting the user to pick their
     // own color here.  Also consider allowing the user to choose the entire set
     // of colors or allowing the user to choose color randomization.
     newIndex = 0;
   }
   _toolbarView.barTintColor = [colors objectAtIndex:newIndex];
 }
 
 // -----------------------------------------------------------------------
+// WebStateObserver implementation.
+
+- (void)didStartProvisionalNavigationForURL:(const GURL&)URL {
+  [self updateToolbar];
+}
+
+- (void)didCommitNavigationWithDetails:
+    (const web::LoadCommittedDetails&)details {
+  [self updateToolbar];
+}
+
+- (void)webStateDidLoadPage:(web::WebState*)webState {
+  DCHECK_EQ(self.webState, webState);
+  [self updateToolbar];
+}
+
+// -----------------------------------------------------------------------
 // WebDelegate implementation.
 
 - (void)webWillAddPendingURL:(const GURL&)url
                   transition:(ui::PageTransition)transition {
 }
 - (void)webDidAddPendingURL {
-  [self updateToolbar];
 }
 - (void)webCancelStartLoadingRequest {
 }
 - (void)webDidStartLoadingURL:(const GURL&)currentUrl
           shouldUpdateHistory:(BOOL)updateHistory {
-  [self updateToolbar];
 }
 - (void)webDidFinishWithURL:(const GURL&)url loadSuccess:(BOOL)loadSuccess {
-  [self updateToolbar];
 }
 
 - (CRWWebController*)webPageOrderedOpen:(const GURL&)url
                                referrer:(const web::Referrer&)referrer
                              windowName:(NSString*)windowName
                            inBackground:(BOOL)inBackground {
   return nil;
 }
 
 - (CRWWebController*)webPageOrderedOpen {
@@ skipping 73 matching lines @@
     runAuthDialogForProtectionSpace:(NSURLProtectionSpace*)protectionSpace
                  proposedCredential:(NSURLCredential*)credential
                   completionHandler:
                       (void (^)(NSString* user, NSString* password))handler {
   // Calling |handler| with nil objects is the same as not implemeting it. This
   // method is implemented to make testing easier.
   handler(nil, nil);
 }
 
 @end