Move _changingHistoryState to superclass.

ios/web/web_state/ui/crw_web_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/web/web_state/ui/crw_web_controller.h"
 
 #import <objc/runtime.h>
 #include <stddef.h>
 
 #include <cmath>
@@ skipping 240 matching lines @@
   // Show overlay view, don't reload web page.
   BOOL _overlayPreviewMode;
   // If |YES|, calls |setShouldSuppressDialogs:YES| when window id is injected
   // into the web view.
   BOOL _shouldSuppressDialogsOnWindowIDInjection;
   // The URL of an expected future recreation of the |webView|. Valid
   // only if the web view was discarded for non-user-visible reasons, such that
   // if the next load request is for that URL, it should be treated as a
   // reconstruction that should use cache aggressively.
   GURL _expectedReconstructionURL;
+  // Whether the web page is currently performing window.history.pushState or
+  // window.history.replaceState
+  // Set to YES on window.history.willChangeState message. To NO on
+  // window.history.didPushState or window.history.didReplaceState.
+  BOOL _changingHistoryState;
 
   scoped_ptr<web::NewWindowInfo> _externalRequest;
 
   // The WebStateImpl instance associated with this CRWWebController.
   scoped_ptr<WebStateImpl> _webStateImpl;
 
   // A set of URLs opened in external applications; stored so that errors
   // from the web view can be identified as resulting from these events.
   base::scoped_nsobject<NSMutableSet> _openedApplicationURL;
 
@@ skipping 1621 matching lines @@
 }
 
 - (BOOL)isBeingDestroyed {
   return _isBeingDestroyed;
 }
 
 - (BOOL)isHalted {
   return _isHalted;
 }
 
+- (BOOL)changingHistoryState {
+  return _changingHistoryState;
+}
+
 - (web::ReferrerPolicy)referrerPolicyFromString:(const std::string&)policy {
   // TODO(stuartmorgan): Remove this temporary bridge to the helper function
   // once the referrer handling moves into the subclasses.
   return web::ReferrerPolicyFromString(policy);
 }
 
 #pragma mark -
 #pragma mark CRWWebControllerContainerViewDelegate
 
 - (CRWWebViewProxyImpl*)contentViewProxyForContainerView:
@@ skipping 478 matching lines @@
 - (BOOL)handleWindowHistoryGoMessage:(base::DictionaryValue*)message
                              context:(NSDictionary*)context {
   int delta;
   message->GetInteger("value", &delta);
   [self goDelta:delta];
   return YES;
 }
 
 - (BOOL)handleWindowHistoryWillChangeStateMessage:(base::DictionaryValue*)unused
                                           context:(NSDictionary*)unusedContext {
   // This dummy handler is a workaround for crbug.com/490673. Issue was

[Eugene But (OOO till 7-30), 2016/03/30 16:56:21]

This comment needs to be revised as handler is not empty anymore.
crbug.com/490673 was probably related to UIWebView. Could you please test with
current up if removing this handler causes crbug.com/490673 to show up again?

[michaeldo, 2016/03/30 17:04:17]

I will re-verify.

[michaeldo, 2016/03/30 21:49:07]

That bug is actually reproducible on master irregardless of this change. I've
removed the comment as it no longer applies.

   // happening when two sequential calls of window.history.pushState were
   // performed by the page. In that case state was changed twice before
   // first change was reported to embedder (and first URL change was reported
   // incorrectly).
 
   // Using dummy handler for window.history.willChangeState message holds
   // second state change until the first change is reported, because messages
   // are queued. This is essentially a sleep, and not the real fix of the
   // problem. TODO(eugenebut): refactor handleWindowHistoryDidPushStateMessage:
   // to avoid this "sleep".
+  _changingHistoryState = YES;
   return YES;
 }
 
 - (BOOL)handleWindowHistoryDidPushStateMessage:(base::DictionaryValue*)message
                                        context:(NSDictionary*)context {
+  DCHECK(_changingHistoryState);
+  _changingHistoryState = NO;
+
   // If there is a pending entry, a new navigation has been registered but
   // hasn't begun loading.  Since the pushState message is coming from the
   // previous page, ignore it and allow the previously registered navigation to
   // continue.  This can ocur if a pushState is issued from an anchor tag
   // onClick event, as the click would have already been registered.
   if ([self sessionController].pendingEntry)
     return NO;
 
   std::string pageURL;
   std::string baseURL;
@@ skipping 61 matching lines @@
          // Notify the observers.
          strongSelf.get()->_webStateImpl->OnHistoryStateChanged();
          [strongSelf didFinishNavigation];
        }];
   return YES;
 }
 
 - (BOOL)handleWindowHistoryDidReplaceStateMessage:
     (base::DictionaryValue*)message
                                           context:(NSDictionary*)context {
+  DCHECK(_changingHistoryState);
+  _changingHistoryState = NO;
+
   std::string pageURL;
   std::string baseURL;
   if (!message->GetString("pageUrl", &pageURL) ||
       !message->GetString("baseUrl", &baseURL)) {
     DLOG(WARNING) << "JS message parameter not found: pageUrl or baseUrl";
     return NO;
   }
   GURL replaceURL = web::history_state_util::GetHistoryStateChangeUrl(
       [self currentURL], GURL(baseURL), pageURL);
   // UIWebView seems to choke on unicode characters that haven't been
@@ skipping 1309 matching lines @@
   if ([MIMEType isEqualToString:@"text/html"] ||
       [MIMEType isEqualToString:@"application/xhtml+xml"] ||
       [MIMEType isEqualToString:@"application/xml"]) {
     return web::WEB_VIEW_DOCUMENT_TYPE_HTML;
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 @end