[ios] fix crash and mismatch incognito/normal in history

Since history always has normal browser state, even in incognito, pass down a
new load strategy forcing incognito from main_controller.
Catch a load in current tab for the other mode and forward to other service.
Fix crash with calling pre-render before checking if we have a web state.

Bug: 960728, 960732, 947005
Change-Id: I591e60ea7bf1e08ac27d6b63b8ba60fffa03e938
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1599466
Commit-Queue: David Jean <djean@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658544}

ios/chrome/app/main_controller.mm

@@ -1480,7 +1480,9 @@ enum class EnterTabSwitcherSnapshotResult {
   _historyCoordinator =
       [[HistoryCoordinator alloc] initWithBaseViewController:self.currentBVC
                                                 browserState:_mainBrowserState];
-  _historyCoordinator.loadStrategy = UrlLoadStrategy::NORMAL;
+  _historyCoordinator.loadStrategy = [self currentPageIsIncognito]
+                                         ? UrlLoadStrategy::ALWAYS_IN_INCOGNITO
+                                         : UrlLoadStrategy::NORMAL;
   _historyCoordinator.dispatcher = self.mainBVC.dispatcher;
   [_historyCoordinator start];
 }

ios/chrome/browser/url_loading/url_loading_params.h

@@ -15,6 +15,7 @@ enum class UrlLoadStrategy {
   NORMAL = 0,
 
   ALWAYS_NEW_FOREGROUND_TAB = 1 << 0,
+  ALWAYS_IN_INCOGNITO = 1 << 1,
 };
 
 // UrlLoadingService wrapper around web::NavigationManager::WebLoadParams,

ios/chrome/browser/url_loading/url_loading_service.mm

@@ -17,6 +17,7 @@
 #import "ios/chrome/browser/url_loading/app_url_loading_service.h"
 #import "ios/chrome/browser/url_loading/url_loading_notifier.h"
 #import "ios/chrome/browser/url_loading/url_loading_params.h"
+#import "ios/chrome/browser/url_loading/url_loading_service_factory.h"
 #import "ios/chrome/browser/url_loading/url_loading_util.h"
 #import "ios/chrome/browser/web/load_timing_tab_helper.h"
 #import "ios/chrome/browser/web_state_list/web_state_list.h"
@@ -84,7 +85,21 @@ void UrlLoadingService::Load(const UrlLoadParams& params) {
       Dispatch(fixed_params);
       break;
     }
-    default: {
+    case UrlLoadStrategy::ALWAYS_IN_INCOGNITO: {
+      ios::ChromeBrowserState* browser_state = browser_->GetBrowserState();
+      if (params.disposition == WindowOpenDisposition::CURRENT_TAB &&
+          !browser_state->IsOffTheRecord()) {
+        UrlLoadingServiceFactory::GetForBrowserState(
+            browser_state->GetOffTheRecordChromeBrowserState())
+            ->Load(params);
+      } else {
+        UrlLoadParams fixed_params = params;
+        fixed_params.in_incognito = YES;
+        Dispatch(fixed_params);
+      }
+      break;
+    }
+    case UrlLoadStrategy::NORMAL: {
       Dispatch(params);
       break;
     }
@@ -128,24 +143,20 @@ void UrlLoadingService::LoadUrlInCurrentTab(const UrlLoadParams& params) {
     return;
   }
 
-  // Ask the prerender service to load this URL if it can, and return if it does
-  // so.
   PrerenderService* prerenderService =
       PrerenderServiceFactory::GetForBrowserState(browser_state);
-  WebStateList* web_state_list = browser_->GetWebStateList();
-  id<SessionWindowRestoring> restorer =
-      (id<SessionWindowRestoring>)browser_->GetTabModel();
-  if (prerenderService && prerenderService->MaybeLoadPrerenderedURL(
-                              web_params.url, web_params.transition_type,
-                              web_state_list, restorer)) {
-    notifier_->TabDidPrerenderUrl(web_params.url, web_params.transition_type);
-    return;
-  }
 
   // Some URLs are not allowed while in incognito.  If we are in incognito and
   // load a disallowed URL, instead create a new tab not in the incognito state.
-  if (browser_state->IsOffTheRecord() &&
-      !IsURLAllowedInIncognito(web_params.url)) {
+  // Also if there's no current web state, that means there is no current tab
+  // to open in, so this also redirects to a new tab.
+  WebStateList* web_state_list = browser_->GetWebStateList();
+  web::WebState* current_web_state = web_state_list->GetActiveWebState();
+  if (!current_web_state || (browser_state->IsOffTheRecord() &&
+                             !IsURLAllowedInIncognito(web_params.url))) {
+    if (prerenderService) {
+      prerenderService->CancelPrerender();
+    }
     notifier_->TabFailedToLoadUrl(web_params.url, web_params.transition_type);
     UrlLoadParams params =
         UrlLoadParams::InNewTab(web_params.url, web_params.virtual_url);
@@ -155,8 +166,16 @@ void UrlLoadingService::LoadUrlInCurrentTab(const UrlLoadParams& params) {
     return;
   }
 
-  web::WebState* current_web_state = web_state_list->GetActiveWebState();
-  DCHECK(current_web_state);
+  // Ask the prerender service to load this URL if it can, and return if it does
+  // so.
+  id<SessionWindowRestoring> restorer =
+      (id<SessionWindowRestoring>)browser_->GetTabModel();
+  if (prerenderService && prerenderService->MaybeLoadPrerenderedURL(
+                              web_params.url, web_params.transition_type,
+                              web_state_list, restorer)) {
+    notifier_->TabDidPrerenderUrl(web_params.url, web_params.transition_type);
+    return;
+  }
 
   BOOL typedOrGeneratedTransition =
       PageTransitionCoreTypeIs(web_params.transition_type,