Fix NTP parentViewController.

ios/chrome/browser/ui/ntp/new_tab_page_controller.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/ui/ntp/new_tab_page_controller.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #import "base/ios/weak_nsobject.h"
 #include "base/logging.h"
@@ skipping 140 matching lines @@
 // Update overlay scroll view value.
 - (void)updateOverlayScrollPosition;
 // Disable the horizontal scroll view.
 - (void)disableScroll;
 // Enable the horizontal scroll view.
 - (void)enableScroll;
 // Returns the ID for the currently selected panel.
 - (NewTabPage::PanelIdentifier)selectedPanelID;
 
 @property(nonatomic, retain) NewTabPageView* ntpView;
+
+// To ease modernizing the NTP only the internal panels are being converted
+// to UIViewControllers.  This means all the plumbing between the
+// BrowserViewController and the internal NTP panels (WebController, NTP)
+// hierarchy is skipped.  While normally the logic to push and pop a view
+// controller would be owned by a coordinator, in this case the old NTP
+// controller adds and removes child view controllers itself when a load
+// is initiated, and when WebController calls -willBeDismissed.
+@property(nonatomic, assign) UIViewController* parentViewController;
+
 @end
 
 @implementation NewTabPageController
 
 @synthesize ntpView = newTabPageView_;
 @synthesize swipeRecognizerProvider = swipeRecognizerProvider_;
 @synthesize parentViewController = parentViewController_;
 
 - (id)initWithUrl:(const GURL&)url
-                loader:(id<UrlLoader>)loader
-               focuser:(id<OmniboxFocuser>)focuser
-           ntpObserver:(id<NewTabPageControllerObserver>)ntpObserver
-          browserState:(ios::ChromeBrowserState*)browserState
-            colorCache:(NSMutableDictionary*)colorCache
-    webToolbarDelegate:(id<WebToolbarDelegate>)webToolbarDelegate
-              tabModel:(TabModel*)tabModel {
+                  loader:(id<UrlLoader>)loader
+                 focuser:(id<OmniboxFocuser>)focuser
+             ntpObserver:(id<NewTabPageControllerObserver>)ntpObserver
+            browserState:(ios::ChromeBrowserState*)browserState
+              colorCache:(NSMutableDictionary*)colorCache
+      webToolbarDelegate:(id<WebToolbarDelegate>)webToolbarDelegate
+                tabModel:(TabModel*)tabModel
+    parentViewController:(UIViewController*)parentViewController {
   self = [super initWithNibName:nil url:url];
   if (self) {
     DCHECK(browserState);
     propertyReleaser_NewTabPageController_.Init(self,
                                                 [NewTabPageController class]);
     browserState_ = browserState;
     loader_ = loader;
     newTabPageObserver_ = ntpObserver;
+    parentViewController_ = parentViewController;
     focuser_.reset(focuser);
     webToolbarDelegate_.reset(webToolbarDelegate);
     tabModel_.reset([tabModel retain]);
     dominantColorCache_ = colorCache;
     self.title = l10n_util::GetNSString(IDS_NEW_TAB_TITLE);
     scrollInitialized_ = NO;
 
     base::scoped_nsobject<UIScrollView> scrollView(
         [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 412)]);
     [scrollView setAutoresizingMask:(UIViewAutoresizingFlexibleWidth |
@@ skipping 297 matching lines @@
 
 - (void)loadControllerWithIndex:(NSUInteger)index {
   if (index >= self.ntpView.tabBar.items.count)
     return;
 
   NewTabPageBarItem* item = [self.ntpView.tabBar.items objectAtIndex:index];
   [self loadPanel:item];
 }
 
 - (BOOL)loadPanel:(NewTabPageBarItem*)item {
+  DCHECK(self.parentViewController);
   UIView* view = nil;
   UIViewController* panelController = nil;
   BOOL created = NO;
   // Only load the controllers once.
   if (item.identifier == NewTabPage::kBookmarksPanel) {
     if (!bookmarkController_) {
       base::scoped_nsobject<BookmarkControllerFactory> factory(
           [[BookmarkControllerFactory alloc] init]);
       bookmarkController_.reset([[factory
           bookmarkPanelControllerForBrowserState:browserState_
@@ skipping 197 matching lines @@
 
 - (void)updateNtpBarShadowForPanelController:
     (id<NewTabPagePanelProtocol>)ntpPanelController {
   if (currentController_ != ntpPanelController)
     return;
   [self.ntpView.tabBar
       setShadowAlpha:[ntpPanelController alphaForBottomShadow]];
 }
 
 @end