Revert of Updated tab history classes to use NavigationItemLists.

ios/chrome/browser/ui/history/tab_history_view_controller.mm

Index: ios/chrome/browser/ui/history/tab_history_view_controller.mm
diff --git a/ios/chrome/browser/ui/history/tab_history_view_controller.mm b/ios/chrome/browser/ui/history/tab_history_view_controller.mm
index 5f84835e3722f9a9a0541c0884779ea516126c50..954ea175ae541159381e16051280b8637e80e1e0 100644
--- a/ios/chrome/browser/ui/history/tab_history_view_controller.mm
+++ b/ios/chrome/browser/ui/history/tab_history_view_controller.mm
@@ -12,6 +12,7 @@
 #import "ios/chrome/browser/ui/history/tab_history_cell.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 #import "ios/third_party/material_components_ios/src/components/Ink/src/MaterialInk.h"
+#import "ios/web/navigation/crw_session_entry.h"
 #include "ios/web/public/favicon_status.h"
 #include "ios/web/public/navigation_item.h"
 #include "ui/gfx/image/image.h"
@@ -26,11 +27,9 @@
 // Tools menu is scrollable.
 const CGFloat kLastRowVisiblePercentage = 0.6;
 // Reuse identifier for cells.
-NSString* const kCellIdentifier = @"TabHistoryCell";
-NSString* const kFooterIdentifier = @"Footer";
-NSString* const kHeaderIdentifier = @"Header";
-// The collection view's a11y label.
-NSString* const kCollectionViewLabel = @"Tab History";
+NSString* cellIdentifier = @"TabHistoryCell";
+NSString* footerIdentifier = @"Footer";
+NSString* headerIdentifier = @"Header";
 // Height of rows.
 const CGFloat kCellHeight = 48.0;
 // Fraction height for partially visible row.
@@ -72,36 +71,6 @@
   return 1.0 / [[UIScreen mainScreen] scale];
 }
 
-// Returns a vector of of NavigationItemLists where the NavigationItems in
-// |items| are separated by host.
-NS_INLINE std::vector<web::NavigationItemList> PartitionItemsByHost(
-    const web::NavigationItemList& items) {
-  std::vector<web::NavigationItemList> partitionedItems;
-  // Used to store the previous host when partitioning NavigationItems.
-  std::string previousHost;
-  // The NavigationItemList containing NavigationItems with the same host.
-  web::NavigationItemList itemsWithSameHostname;
-  // Separate the items in |items| by host.
-  for (web::NavigationItem* item : items) {
-    std::string currentHost = item->GetURL().host();
-    if (previousHost.empty())
-      previousHost = currentHost;
-    // TODO: This should use some sort of Top Level Domain matching instead of
-    // explicit host match so that images.googe.com matches shopping.google.com.
-    if (previousHost == currentHost) {
-      itemsWithSameHostname.push_back(item);
-    } else {
-      partitionedItems.push_back(itemsWithSameHostname);
-      itemsWithSameHostname = web::NavigationItemList(1, item);
-      previousHost = currentHost;
-    }
-  }
-  // Add the last list contiaining the same host.
-  if (!itemsWithSameHostname.empty())
-    partitionedItems.push_back(itemsWithSameHostname);
-  return partitionedItems;
-}
-
 }  // namespace
 
 @interface TabHistoryViewControllerLayout : UICollectionViewLayout
@@ -250,50 +219,15 @@
 
 @interface TabHistoryViewController ()<MDCInkTouchControllerDelegate> {
   MDCInkTouchController* _inkTouchController;
-  // A vector of NavigationItemLists where the NavigationItems are separated
-  // by hostname.
-  std::vector<web::NavigationItemList> _partitionedItems;
-}
-
-// Returns the NavigationItem corresponding with |indexPath|.
-- (const web::NavigationItem*)itemAtIndexPath:(NSIndexPath*)indexPath;
-
-// Removes all NavigationItem pointers from this class.  Tapping a cell that
-// triggers a navigation may delete NavigationItems, so NavigationItem
-// references should be reset to avoid use-after-free errors.
-- (void)clearNavigationItems;
-
+  NSArray* _partitionedEntries;
+  NSArray* _sessionEntries;
+}
 @end
 
 @implementation TabHistoryViewController
 
-- (instancetype)initWithItems:(const web::NavigationItemList&)items {
-  TabHistoryViewControllerLayout* layout =
-      [[TabHistoryViewControllerLayout alloc] init];
-  if ((self = [super initWithCollectionViewLayout:layout])) {
-    // Populate |_partitionedItems|.
-    _partitionedItems = PartitionItemsByHost(items);
-
-    // Set up the UICollectionView.
-    UICollectionView* collectionView = [self collectionView];
-    collectionView.accessibilityLabel = kCollectionViewLabel;
-    collectionView.backgroundColor = [UIColor whiteColor];
-    [collectionView registerClass:[TabHistoryCell class]
-        forCellWithReuseIdentifier:kCellIdentifier];
-    [collectionView registerClass:[TabHistorySectionHeader class]
-        forSupplementaryViewOfKind:UICollectionElementKindSectionHeader
-               withReuseIdentifier:kHeaderIdentifier];
-    [collectionView registerClass:[TabHistorySectionFooter class]
-        forSupplementaryViewOfKind:UICollectionElementKindSectionFooter
-               withReuseIdentifier:kFooterIdentifier];
-
-    // Set up the ink controller.
-    _inkTouchController =
-        [[MDCInkTouchController alloc] initWithView:collectionView];
-    [_inkTouchController setDelegate:self];
-    [_inkTouchController addInkView];
-  }
-  return self;
+- (NSArray*)sessionEntries {
+  return _sessionEntries;
 }
 
 #pragma mark Public Methods
@@ -302,8 +236,9 @@
   DCHECK(suggestedHeight >= kCellHeight);
   CGFloat optimalHeight = 0;
 
-  for (web::NavigationItemList& itemsWithSameHost : _partitionedItems) {
-    for (size_t count = 0; count < itemsWithSameHost.size(); ++count) {
+  for (NSArray* sectionArray in _partitionedEntries) {
+    NSUInteger sectionItemCount = [sectionArray count];
+    for (NSUInteger i = 0; i < sectionItemCount; ++i) {
       CGFloat proposedHeight = optimalHeight + kCellHeight;
 
       if (proposedHeight > suggestedHeight) {
@@ -328,65 +263,151 @@
   return optimalHeight;
 }
 
+- (instancetype)init {
+  TabHistoryViewControllerLayout* layout =
+      [[TabHistoryViewControllerLayout alloc] init];
+
+  return [self initWithCollectionViewLayout:layout];
+}
+
+- (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout*)layout {
+  self = [super initWithCollectionViewLayout:layout];
+  if (self) {
+    UICollectionView* collectionView = [self collectionView];
+    [collectionView setBackgroundColor:[UIColor whiteColor]];
+
+    [collectionView registerClass:[TabHistoryCell class]
+        forCellWithReuseIdentifier:cellIdentifier];
+
+    [collectionView registerClass:[TabHistorySectionHeader class]
+        forSupplementaryViewOfKind:UICollectionElementKindSectionHeader
+               withReuseIdentifier:headerIdentifier];
+
+    [collectionView registerClass:[TabHistorySectionFooter class]
+        forSupplementaryViewOfKind:UICollectionElementKindSectionFooter
+               withReuseIdentifier:footerIdentifier];
+
+    _inkTouchController =
+        [[MDCInkTouchController alloc] initWithView:collectionView];
+    [_inkTouchController setDelegate:self];
+    [_inkTouchController addInkView];
+  }
+
+  return self;
+}
+
 #pragma mark UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
     didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
-  TabHistoryCell* cell = base::mac::ObjCCastStrict<TabHistoryCell>(
-      [collectionView cellForItemAtIndexPath:indexPath]);
+  UICollectionViewCell* cell =
+      [collectionView cellForItemAtIndexPath:indexPath];
   [collectionView chromeExecuteCommand:cell];
-  [self clearNavigationItems];
 }
 
 #pragma mark UICollectionViewDataSource
+
+- (CRWSessionEntry*)entryForIndexPath:(NSIndexPath*)indexPath {
+  NSInteger section = [indexPath section];
+  NSInteger item = [indexPath item];
+
+  DCHECK(section < (NSInteger)[_partitionedEntries count]);
+  DCHECK(item < (NSInteger)[[_partitionedEntries objectAtIndex:section] count]);
+  NSArray* sectionedArray = [_partitionedEntries objectAtIndex:section];
+
+  return [sectionedArray objectAtIndex:item];
+}
 
 - (NSInteger)collectionView:(UICollectionView*)collectionView
      numberOfItemsInSection:(NSInteger)section {
-  size_t sectionIdx = static_cast<size_t>(section);
-  DCHECK_LT(sectionIdx, _partitionedItems.size());
-  return _partitionedItems[sectionIdx].size();
+  DCHECK(section < (NSInteger)[_partitionedEntries count]);
+  return [[_partitionedEntries objectAtIndex:section] count];
 }
 
 - (UICollectionViewCell*)collectionView:(UICollectionView*)collectionView
                  cellForItemAtIndexPath:(NSIndexPath*)indexPath {
   TabHistoryCell* cell =
-      [collectionView dequeueReusableCellWithReuseIdentifier:kCellIdentifier
+      [collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier
                                                 forIndexPath:indexPath];
-  cell.item = [self itemAtIndexPath:indexPath];
-  cell.tag = IDC_BACK_FORWARD_IN_TAB_HISTORY;
+
+  [cell setEntry:[self entryForIndexPath:indexPath]];
+  [cell setTag:IDC_BACK_FORWARD_IN_TAB_HISTORY];
+
   return cell;
 }
 
 - (NSInteger)numberOfSectionsInCollectionView:(UICollectionView*)view {
-  return _partitionedItems.size();
+  return [_partitionedEntries count];
 }
 
 - (UICollectionReusableView*)collectionView:(UICollectionView*)view
           viewForSupplementaryElementOfKind:(NSString*)kind
                                 atIndexPath:(NSIndexPath*)indexPath {
-  // Return a footer cell if requested.
   if ([kind isEqualToString:UICollectionElementKindSectionFooter]) {
     return [view dequeueReusableSupplementaryViewOfKind:kind
-                                    withReuseIdentifier:kFooterIdentifier
+                                    withReuseIdentifier:footerIdentifier
                                            forIndexPath:indexPath];
   }
+
   DCHECK([kind isEqualToString:UICollectionElementKindSectionHeader]);
-
-  // Dequeue a header cell and populate its favicon image.
+  CRWSessionEntry* sessionEntry = [self entryForIndexPath:indexPath];
+  web::NavigationItem* navigationItem = [sessionEntry navigationItem];
+
   TabHistorySectionHeader* header =
       [view dequeueReusableSupplementaryViewOfKind:kind
-                               withReuseIdentifier:kHeaderIdentifier
+                               withReuseIdentifier:headerIdentifier
                                       forIndexPath:indexPath];
+
   UIImage* iconImage = nil;
-  const gfx::Image& image =
-      [self itemAtIndexPath:indexPath]->GetFavicon().image;
+  const gfx::Image& image = navigationItem->GetFavicon().image;
   if (!image.IsEmpty())
     iconImage = image.ToUIImage();
   else
     iconImage = [UIImage imageNamed:@"default_favicon"];
+
   [[header iconView] setImage:iconImage];
 
   return header;
+}
+
+- (void)setSessionEntries:(NSArray*)sessionEntries {
+  _sessionEntries = sessionEntries;
+
+  std::string previousHost;
+
+  NSMutableArray* sectionArray = [NSMutableArray array];
+  NSMutableArray* partitionedEntries = [NSMutableArray array];
+
+  NSInteger numberOfEntries = [_sessionEntries count];
+  for (NSInteger index = 0; index < numberOfEntries; ++index) {
+    CRWSessionEntry* sessionEntry = [_sessionEntries objectAtIndex:index];
+    web::NavigationItem* navigationItem = [sessionEntry navigationItem];
+
+    std::string currentHost;
+    if (navigationItem)
+      currentHost = navigationItem->GetURL().host();
+
+    if (previousHost.empty())
+      previousHost = currentHost;
+
+    // TODO: This should use some sort of Top Level Domain matching instead of
+    // explicit host match so that images.googe.com matches shopping.google.com.
+    if (previousHost == currentHost) {
+      [sectionArray addObject:sessionEntry];
+    } else {
+      [partitionedEntries addObject:sectionArray];
+      sectionArray = [NSMutableArray arrayWithObject:sessionEntry];
+      previousHost = currentHost;
+    }
+  }
+
+  if ([sectionArray count])
+    [partitionedEntries addObject:sectionArray];
+
+  if (![partitionedEntries count])
+    partitionedEntries = nil;
+
+  _partitionedEntries = partitionedEntries;
 }
 
 #pragma mark MDCInkTouchControllerDelegate
@@ -410,22 +431,4 @@
   return YES;
 }
 
-#pragma mark -
-
-- (const web::NavigationItem*)itemAtIndexPath:(NSIndexPath*)indexPath {
-  size_t section = static_cast<size_t>([indexPath section]);
-  size_t item = static_cast<size_t>([indexPath item]);
-  DCHECK_LT(section, _partitionedItems.size());
-  DCHECK_LT(item, _partitionedItems[section].size());
-  return _partitionedItems[section][item];
-}
-
-- (void)clearNavigationItems {
-  _partitionedItems.clear();
-  for (UICollectionViewCell* cell in self.collectionView.visibleCells) {
-    TabHistoryCell* historyCell = base::mac::ObjCCast<TabHistoryCell>(cell);
-    historyCell.item = nullptr;
-  }
-}
-
 @end