Implement request mobile site.

ios/chrome/browser/tabs/tab.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/chrome/browser/tabs/tab.h"
 
 #import <CoreLocation/CoreLocation.h>
 #import <UIKit/UIKit.h>
 
 #include <utility>
@@ skipping 180 matching lines @@
   BACKGROUND_TAB_BACKGROUND_APP,
   TERMINATION_TAB_STATE_COUNT
 };
 
 // Returns true if the application is in the background or inactive state.
 bool IsApplicationStateNotActive(UIApplicationState state) {
   return (state == UIApplicationStateBackground ||
           state == UIApplicationStateInactive);
 }
 
+// Returns true if |item| is the result of a HTTP redirect.
+// Returns false if |item| is nullptr;
+bool IsItemRedirectItem(web::NavigationItem* item) {
+  if (!item)
+    return false;
+
+  return (ui::PageTransition::PAGE_TRANSITION_IS_REDIRECT_MASK &
+          item->GetTransitionType()) == 0;
+}
 }  // namespace
 
 @interface Tab ()<CRWWebStateObserver,
                   CRWWebControllerObserver,
                   FindInPageControllerDelegate,
                   ReaderModeControllerDelegate> {
   TabModel* parentTabModel_;               // weak
   ios::ChromeBrowserState* browserState_;  // weak
 
   base::scoped_nsobject<OpenInController> openInController_;
@@ skipping 1140 matching lines @@
 
 - (BOOL)usesDesktopUserAgent {
   if (!self.navigationManager)
     return NO;
 
   web::NavigationItem* visibleItem = self.navigationManager->GetVisibleItem();
   return visibleItem &&
          visibleItem->GetUserAgentType() == web::UserAgentType::DESKTOP;
 }
 
-- (void)reloadForDesktopUserAgent {
+- (void)reloadWithUserAgentType:(web::UserAgentType)userAgentType {
   // This removes the web view, which will be recreated at the end of this.
   [self.webController requirePageReconstruction];
 
   // TODO(crbug.com/228171): A hack in session_controller -addPendingItem
   // discusses making tab responsible for distinguishing history stack
   // navigation from new navigations.
   web::NavigationManager* navigationManager = [self navigationManager];
   DCHECK(navigationManager);
-  web::NavigationItem* lastNonRedirectedItem =
-      GetLastCommittedNonRedirectedItem(navigationManager);
-  if (!lastNonRedirectedItem)
+
+  web::NavigationItem* lastNonRedirectItem =
+      navigationManager->GetTransientItem();
+  if (!lastNonRedirectItem || IsItemRedirectItem(lastNonRedirectItem))
+    lastNonRedirectItem = navigationManager->GetPendingItem();

[Eugene But (OOO till 7-30), 2017/04/11 02:11:56]

Should this be GetVisibleItem instead? Pending url is not necessarily displayed
in the omnibox.

[liaoyuke, 2017/04/11 18:27:20]

Good catch!

+  if (!lastNonRedirectItem || IsItemRedirectItem(lastNonRedirectItem))
+    lastNonRedirectItem = GetLastCommittedNonRedirectedItem(navigationManager);
+
+  if (!lastNonRedirectItem)
     return;
 
   // |reloadURL| will be empty if a page was open by DOM.
-  GURL reloadURL(lastNonRedirectedItem->GetOriginalRequestURL());
+  GURL reloadURL(lastNonRedirectItem->GetOriginalRequestURL());
   if (reloadURL.is_empty()) {
     DCHECK(self.webState && self.webState->HasOpener());
-    reloadURL = lastNonRedirectedItem->GetVirtualURL();
+    reloadURL = lastNonRedirectItem->GetVirtualURL();
   }
 
   web::NavigationManager::WebLoadParams params(reloadURL);
-  params.referrer = lastNonRedirectedItem->GetReferrer();
-  // A new navigation is needed here for reloading with desktop User-Agent.
-  params.user_agent_override_option =
-      web::NavigationManager::UserAgentOverrideOption::DESKTOP;
-  params.transition_type =
-      ui::PageTransitionFromInt(ui::PAGE_TRANSITION_FORM_SUBMIT);
+  params.referrer = lastNonRedirectItem->GetReferrer();
+  params.transition_type = ui::PAGE_TRANSITION_RELOAD;
+
+  switch (userAgentType) {
+    case web::UserAgentType::DESKTOP:
+      params.user_agent_override_option =
+          web::NavigationManager::UserAgentOverrideOption::DESKTOP;
+      break;
+    case web::UserAgentType::MOBILE:
+      params.user_agent_override_option =
+          web::NavigationManager::UserAgentOverrideOption::MOBILE;
+      break;
+    case web::UserAgentType::NONE:
+      NOTREACHED();
+  }
+
   navigationManager->LoadURLWithParams(params);
 }
 
 - (id<SnapshotOverlayProvider>)snapshotOverlayProvider {
   return snapshotOverlayProvider_.get();
 }
 
 - (void)setSnapshotOverlayProvider:
     (id<SnapshotOverlayProvider>)snapshotOverlayProvider {
   snapshotOverlayProvider_.reset(snapshotOverlayProvider);
@@ skipping 561 matching lines @@
 
 - (TabModel*)parentTabModel {
   return parentTabModel_;
 }
 
 - (FormInputAccessoryViewController*)inputAccessoryViewController {
   return inputAccessoryViewController_.get();
 }
 
 @end