Always set the serialized state object for history navigations.

ios/web/web_state/ui/crw_web_controller.h

Index: ios/web/web_state/ui/crw_web_controller.h
diff --git a/ios/web/web_state/ui/crw_web_controller.h b/ios/web/web_state/ui/crw_web_controller.h
index b7d5225fa6d3728f876f26636b18f51bc9b46ef2..27aef98e074f19576334e59df4b4cf346a3ee3bb 100644
--- a/ios/web/web_state/ui/crw_web_controller.h
+++ b/ios/web/web_state/ui/crw_web_controller.h
@@ -185,12 +185,14 @@ class WebStateImpl;
 
 // Loads the URL indicated by current session state.
 - (void)loadCurrentURL;
-// Updates UIWebView's URL and urlOnStartLoading_ during back/forward navigation
-// over pushed URLs. Needed so that sites that depend on URL params/fragment
-// continue to work correctly and checks for the URL don't incorrectly trigger
-// -pageChanged calls.
-- (void)finishPushStateNavigationToURL:(const GURL&)url
-                       withStateObject:(NSString*)stateObject;
+// Injects JavaScript into the web view to update the URL to |url|, to set
+// window.history.state to |stateObject|, and to trigger a popstate() event.
+// Upon the scripts completion, resets |urlOnStartLoading_| and
+// |_lastRegisteredRequestURL| to |url|.  This is necessary so that sites that
+// depend on URL params/fragments continue to work correctly and that checks for
+// the URL don't incorrectly trigger |-pageChanged| calls.
+- (void)setPushedOrReplacedURL:(const GURL&)url

[Eugene But (OOO till 7-30), 2015/09/18 02:02:35]

Since this method is not called anywhere, lets take a chance to move it to
implementation file.

[Eugene But (OOO till 7-30), 2015/09/18 02:02:36]

NIT: s/url/URL (including changes in the comments)

[kkhorimoto, 2015/09/21 22:55:13]

Done.

+                   stateObject:(NSString*)stateObject;
 // Loads the HTML into the page.
 - (void)loadHTML:(NSString*)html;
 // Loads HTML in the page and presents it as if it was originating from an
@@ -301,7 +303,7 @@ class WebStateImpl;
 
 // Helper method called at the end of history navigation methods goBack,
 // goForward, and goDelta. Determines whether to load a new URL or call
-// |finishPushStateNavigationToURL:withStateObject:|. |fromEntry| is the
+// |setPushedOrReplacedURL:stateObject:|. |fromEntry| is the

[Eugene But (OOO till 7-30), 2015/09/18 02:02:36]

NIT: I think mentioning setPushedOrReplacedURL:stateObject: is unnecessary here
(especially if you move that method to implementation file).

[kkhorimoto, 2015/09/21 22:55:13]

Done.

 // CRWSessionEntry that was the current entry prior to the navigation.
 // TODO(rohitrao): This is only exposed so Tab can call it temporarily.  Remove
 // as soon as all the Tab calls have moved into CRWWebController.