[iOS] Refactoring web CRWSessionController user agent code.

ios/web/navigation/crw_session_controller.mm

Index: ios/web/navigation/crw_session_controller.mm
diff --git a/ios/web/navigation/crw_session_controller.mm b/ios/web/navigation/crw_session_controller.mm
index aa98921e620a5bc72c68361aaeca35d56bf95462..fdac04d133848210783972b64263d9a390bc9868 100644
--- a/ios/web/navigation/crw_session_controller.mm
+++ b/ios/web/navigation/crw_session_controller.mm
@@ -114,7 +114,6 @@ - (void)discardTransientItem;
 - (CRWSessionEntry*)sessionEntryWithURL:(const GURL&)url
                                referrer:(const web::Referrer&)referrer
                              transition:(ui::PageTransition)transition
-                    useDesktopUserAgent:(BOOL)useDesktopUserAgent
                       rendererInitiated:(BOOL)rendererInitiated;
 // Returns YES if the PageTransition for the underlying navigationItem at
 // |index| in |entries_| has ui::PAGE_TRANSITION_IS_REDIRECT_MASK.
@@ -367,10 +366,17 @@ - (void)addPendingItem:(const GURL&)url
   CRWSessionEntry* currentEntry = self.currentEntry;
   if (currentEntry) {
     web::NavigationItem* item = [currentEntry navigationItem];
-    if (item->GetURL() == url &&
-        (!PageTransitionCoreTypeIs(trans, ui::PAGE_TRANSITION_FORM_SUBMIT) ||
-         PageTransitionCoreTypeIs(item->GetTransitionType(),
-                                  ui::PAGE_TRANSITION_FORM_SUBMIT))) {
+
+    BOOL hasSameURL = item->GetURL() == url;
+    BOOL isPendingTransitionFormSubmit =
+        PageTransitionCoreTypeIs(trans, ui::PAGE_TRANSITION_FORM_SUBMIT);
+    BOOL isCurrentTransitionFormSubmit = PageTransitionCoreTypeIs(
+        item->GetTransitionType(), ui::PAGE_TRANSITION_FORM_SUBMIT);
+    BOOL shouldCreatePendingItem =
+        !hasSameURL ||
+        (isPendingTransitionFormSubmit && !isCurrentTransitionFormSubmit);
+
+    if (!shouldCreatePendingItem) {
       // Send the notification anyway, to preserve old behavior. It's unknown
       // whether anything currently relies on this, but since both this whole
       // hack and the content facade will both be going away, it's not worth
@@ -382,15 +388,9 @@ - (void)addPendingItem:(const GURL&)url
     }
   }
 
-  BOOL useDesktopUserAgent =
-      _useDesktopUserAgentForNextPendingItem ||
-      (self.currentEntry.navigationItem &&
-       self.currentEntry.navigationItem->IsOverridingUserAgent());
-  _useDesktopUserAgentForNextPendingItem = NO;
   _pendingEntry.reset([self sessionEntryWithURL:url
                                        referrer:ref
                                      transition:trans
-                            useDesktopUserAgent:useDesktopUserAgent
                               rendererInitiated:rendererInitiated]);
 
   if (_navigationManager && _navigationManager->GetFacadeDelegate()) {
@@ -484,7 +484,6 @@ - (void)addTransientItemWithURL:(const GURL&)URL {
       sessionEntryWithURL:URL
                  referrer:web::Referrer()
                transition:ui::PAGE_TRANSITION_CLIENT_REDIRECT
-      useDesktopUserAgent:NO
         rendererInitiated:NO]);
 
   web::NavigationItem* navigationItem = [_transientEntry navigationItem];
@@ -502,15 +501,17 @@ - (void)pushNewItemWithURL:(const GURL&)URL
   CHECK(
       web::history_state_util::IsHistoryStateChangeValid(item->GetURL(), URL));
   web::Referrer referrer(item->GetURL(), web::ReferrerPolicyDefault);
-  bool overrideUserAgent =
-      self.currentEntry.navigationItem->IsOverridingUserAgent();
+
   base::scoped_nsobject<CRWSessionEntry> pushedEntry([self
       sessionEntryWithURL:URL
                  referrer:referrer
                transition:transition
-      useDesktopUserAgent:overrideUserAgent
         rendererInitiated:NO]);
+
   web::NavigationItemImpl* pushedItem = [pushedEntry navigationItemImpl];
+  bool overrideUserAgent =
+      self.currentEntry.navigationItem->IsOverridingUserAgent();

[Eugene But (OOO till 7-30), 2017/02/16 02:20:48]

nit: How about this?:
pushedItem->SetIsOverridingUserAgent(currentItem->IsOverridingUserAgent());

[liaoyuke, 2017/02/16 22:04:29]

Done.

+  pushedItem->SetIsOverridingUserAgent(overrideUserAgent);
   pushedItem->SetSerializedStateObject(stateObject);
   pushedItem->SetIsCreatedFromPushState(true);
   web::SSLStatus& sslStatus = [self currentEntry].navigationItem->GetSSL();
@@ -679,13 +680,6 @@ - (CRWSessionEntry*)lastUserEntry {
   return [_entries objectAtIndex:index];
 }
 
-- (void)useDesktopUserAgentForNextPendingItem {
-  if (_pendingEntry)
-    [_pendingEntry navigationItem]->SetIsOverridingUserAgent(true);
-  else
-    _useDesktopUserAgentForNextPendingItem = YES;
-}
-
 - (NSInteger)indexOfItem:(const web::NavigationItem*)item {
   web::NavigationItemList items = self.items;
   for (NSInteger i = 0; i < static_cast<NSInteger>(items.size()); ++i) {
@@ -712,7 +706,6 @@ - (NSString*)uniqueID {
 - (CRWSessionEntry*)sessionEntryWithURL:(const GURL&)url
                                referrer:(const web::Referrer&)referrer
                              transition:(ui::PageTransition)transition
-                    useDesktopUserAgent:(BOOL)useDesktopUserAgent
                       rendererInitiated:(BOOL)rendererInitiated {
   GURL loaded_url(url);
   BOOL urlWasRewritten = NO;
@@ -733,7 +726,6 @@ - (CRWSessionEntry*)sessionEntryWithURL:(const GURL&)url
   item->SetURL(loaded_url);
   item->SetReferrer(referrer);
   item->SetTransitionType(transition);
-  item->SetIsOverridingUserAgent(useDesktopUserAgent);
   item->set_is_renderer_initiated(rendererInitiated);
   return [[CRWSessionEntry alloc] initWithNavigationItem:std::move(item)];
 }