Connect ContentSuggestionsMediator to the ContentService

ios/chrome/browser/ui/content_suggestions/content_suggestions_section_information.h

 // Copyright 2017 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CONTENT_SUGGESTIONS_SECTION_INFORMATION_H_
 #define IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CONTENT_SUGGESTIONS_SECTION_INFORMATION_H_
 
 #import <Foundation/Foundation.h>
 
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_item.h"
 
 // Layout for the section and its items.
 typedef NS_ENUM(NSInteger, ContentSuggestionsSectionLayout) {
   // Follows the card layout.
   ContentSuggestionsSectionLayoutCard,
   // No specific layout.
   ContentSuggestionsSectionLayoutCustom,
 };
 
 // This enum is used for ordering the sections and as ID for the section. Make
 // all sections in the same collection have different ID.
 // When adding a new kind of suggestions, add a new corresponding section. The
 // ordering is not persisted between launch, reordering is possible.
 typedef NS_ENUM(NSInteger, ContentSuggestionsSectionID) {
   ContentSuggestionsSectionBookmarks = 0,
   ContentSuggestionsSectionArticles = 1,
 
   // Do not use this. It will trigger a DCHECK.
   // Do not add value after this one.
-  ContentSuggestionsSectionCount
+  ContentSuggestionsSectionUnknown
 };
 
 // Contains the information needed to display the section.
 @interface ContentSuggestionsSectionInformation : NSObject
 
 - (instancetype)initWithID:(ContentSuggestionsSectionID)ID
-                 emptyCell:(CollectionViewItem*)emptyCell
-                    layout:(ContentSuggestionsSectionLayout)layout
-                     title:(NSString*)title NS_DESIGNATED_INITIALIZER;
+    NS_DESIGNATED_INITIALIZER;
 - (instancetype)init NS_UNAVAILABLE;
 
 // Item to display when the section is empty. If nil the section should not be
 // displayed when empty.
-@property(nonatomic, strong, readonly) CollectionViewItem* emptyCell;
+@property(nonatomic, strong) CollectionViewItem* emptyCell;

[stkhapugin, 2017/02/15 15:35:43]

Why are these not readonly anymore? Can these be modified after creation? 

[gambard, 2017/02/16 10:06:30]

No, but the creation is in multiple steps (see ContentSuggestionsMediator's
SectionInformationFromCategoryInfo), it is easier to set the property this way.
And none of them are mandatory.

[stkhapugin, 2017/02/16 10:53:27]

So you agree that it's better and safer to make everything readonly, but you
won't do this because in one method where you instantiate this class you don't
want to create a few local variables? :)

 // Layout to display the content of the section.
-@property(nonatomic, assign, readonly) ContentSuggestionsSectionLayout layout;
+@property(nonatomic, assign) ContentSuggestionsSectionLayout layout;
 // ID of the section. Used for ordering.
 @property(nonatomic, assign, readonly) ContentSuggestionsSectionID ID;
 // Title for the section.
-@property(nonatomic, copy, readonly) NSString* title;
+@property(nonatomic, copy) NSString* title;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CONTENT_SUGGESTIONS_SECTION_INFORMATION_H_