Revert of Always set the navigation pending item for page reload. (pa…

…tchset #6 id:220001 of https://codereview.chromium.org/2931833004/ )

Reason for revert:
introduced crbug/750775

Original issue's description:
> Always set the navigation pending item for page reload.
>
> Set the pendingItemIndex to the last committed item in case of page reload
> and on the case of application open/tab out of memory reopened.
>
> This doesn't solve the PendingItem being null problem entirely there are still
> couple cases when that can happen and they are not page reloads.
>
> CL 1/2
>
> BUG=676129
>
> Review-Url: https://codereview.chromium.org/2931833004
> Cr-Commit-Position: refs/heads/master@{#486777}
> Committed: https://chromium.googlesource.com/chromium/src/+/bc2e0a45e23c739bb3c04d119d43abbb01398289

TBR=eugenebut@chromium.org,kkhorimoto@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=676129

Review-Url: https://codereview.chromium.org/2998463002
Cr-Commit-Position: refs/heads/master@{#492138}

ios/web/web_state/navigation_callbacks_inttest.mm

@@ -87,9 +87,15 @@
   EXPECT_FALSE((*context)->GetError());
   ASSERT_FALSE((*context)->GetResponseHeaders());
   ASSERT_TRUE(web_state->IsLoading());
-  NavigationManager* navigation_manager = web_state->GetNavigationManager();
-  NavigationItem* item = navigation_manager->GetPendingItem();
-  EXPECT_EQ(url, item->GetURL());
+  // TODO(crbug.com/676129): Reload does not create a pending item. Remove this
+  // workaround once the bug is fixed.
+  if (!ui::PageTransitionTypeIncludingQualifiersIs(
+          ui::PageTransition::PAGE_TRANSITION_RELOAD,
+          (*context)->GetPageTransition())) {
+    NavigationManager* navigation_manager = web_state->GetNavigationManager();
+    NavigationItem* item = navigation_manager->GetPendingItem();
+    EXPECT_EQ(url, item->GetURL());
+  }
 }
 
 // Verifies correctness of |NavigationContext| (|arg0|) for navigations via POST
@@ -211,8 +217,9 @@
   EXPECT_FALSE((*context)->IsSameDocument());
   EXPECT_FALSE((*context)->GetError());
   EXPECT_FALSE((*context)->GetResponseHeaders());
-  EXPECT_EQ(web_state->GetNavigationManager()->GetPendingItem(),
-            web_state->GetNavigationManager()->GetLastCommittedItem());
+  // TODO(crbug.com/676129): Reload does not create a pending item. Check
+  // pending item once the bug is fixed.
+  EXPECT_FALSE(web_state->GetNavigationManager()->GetPendingItem());
 }
 
 // Verifies correctness of |NavigationContext| (|arg0|) for reload navigation

ios/web/web_state/ui/crw_web_controller.mm

@@ -1517,18 +1517,11 @@ - (double)loadingProgress {
     // Typically on PAGE_TRANSITION_CLIENT_REDIRECT.
     [[self sessionController] updatePendingItem:requestURL];
   } else {
-    // If this is a reload then there no need to create a new pending item,
-    // instead update the pending item to the last committed item.
-    if (PageTransitionCoreTypeIs(transition, ui::PAGE_TRANSITION_RELOAD)) {
-      self.sessionController.pendingItemIndex =
-          self.sessionController.lastCommittedItemIndex;
-    } else {
-      // A new session history entry needs to be created.
-      self.navigationManagerImpl->AddPendingItem(
-          requestURL, referrer, transition,
-          web::NavigationInitiationType::RENDERER_INITIATED,
-          web::NavigationManager::UserAgentOverrideOption::INHERIT);
-    }
+    // A new session history entry needs to be created.
+    self.navigationManagerImpl->AddPendingItem(
+        requestURL, referrer, transition,
+        web::NavigationInitiationType::RENDERER_INITIATED,
+        web::NavigationManager::UserAgentOverrideOption::INHERIT);
   }
   std::unique_ptr<web::NavigationContextImpl> context =
       web::NavigationContextImpl::CreateNavigationContext(
@@ -1986,11 +1979,6 @@ - (void)triggerPendingLoad {
     BOOL isChromeScheme =
         web::GetWebClient()->IsAppSpecificURL(currentNavigationURL);
 
-    // Since this is implicit reload, no new pending item should be created, set
-    // the pending item index to the last committed item.
-    self.sessionController.pendingItemIndex =
-        self.sessionController.lastCommittedItemIndex;
-
     // Don't immediately load the web page if in overlay mode. Always load if
     // native.
     if (isChromeScheme || !_overlayPreviewMode) {
@@ -2032,10 +2020,6 @@ - (void)reload {
   _lastUserInteraction.reset();
   base::RecordAction(UserMetricsAction("Reload"));
   GURL url = self.currentNavItem->GetURL();
-  // Reloading shouldn't create create a new pending item, instead set the
-  // pending item index to the last committed item.
-  self.sessionController.pendingItemIndex =
-      self.sessionController.lastCommittedItemIndex;
   if ([self shouldLoadURLInNativeView:url]) {
     std::unique_ptr<web::NavigationContextImpl> navigationContext = [self
         registerLoadRequestForURL:url