Add ContentSuggestionsMediator

ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm

 // Copyright 2016 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/content_suggestions/content_suggestions_view_controller.h"
 
 #include "base/mac/foundation_util.h"
 #import "ios/chrome/browser/ui/collection_view/cells/MDCCollectionViewCell+Chrome.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_item.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
@@ skipping 22 matching lines @@
 // according to |expand|.
 - (void)expand:(BOOL)expand cell:(UICollectionViewCell*)cell;
 
 @end
 
 @implementation ContentSuggestionsViewController
 
 @synthesize suggestionCommandHandler = _suggestionCommandHandler;
 @synthesize collectionUpdater = _collectionUpdater;
 
+- (instancetype)initWithStyle:(CollectionViewControllerStyle)style
+                   dataSource:(id<ContentSuggestionsDataSource>)dataSource {
+  self = [super initWithStyle:style];
+  if (self) {
+    _collectionUpdater = [[ContentSuggestionsCollectionUpdater alloc]
+        initWithDataSource:dataSource];
+  }
+  return self;
+}
+
 #pragma mark - UIViewController
 
 - (void)viewDidLoad {
   [super viewDidLoad];
 
-  _collectionUpdater = [[ContentSuggestionsCollectionUpdater alloc] init];
   _collectionUpdater.collectionViewController = self;
 
   self.collectionView.delegate = self;
   self.styler.cellStyle = MDCCollectionViewCellStyleCard;
 }
 
 #pragma mark - UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
     didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
@@ skipping 96 matching lines @@
 
     [UIView
         animateWithDuration:kAnimationDuration
                  animations:^{
                    [self.collectionView.collectionViewLayout invalidateLayout];
                  }];
   }
 }
 
 @end