Connect ContentSuggestionsMediator to the ContentService

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

 // 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.
 
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_section_information.h"
 
 #include "base/logging.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 @implementation ContentSuggestionsSectionInformation
 
 @synthesize emptyCell = _emptyCell;
 @synthesize layout = _layout;
 @synthesize ID = _ID;

[marq (ping after 24h), 2017/02/16 13:14:36]

Usually I like shorter names, but 'ID' (and especially '_ID') looks like it
might mean something special (like _cmd does), even though it actually doesn't.
I'd find it a bit more readable if it were 'sectionID' instead. 

[gambard, 2017/02/16 13:45:53]

Done.

 @synthesize title = _title;
 
-- (instancetype)initWithID:(ContentSuggestionsSectionID)ID
-                 emptyCell:(CollectionViewItem*)emptyCell
-                    layout:(ContentSuggestionsSectionLayout)layout
-                     title:(NSString*)title {
+- (instancetype)initWithID:(ContentSuggestionsSectionID)ID {
   self = [super init];
   if (self) {
-    DCHECK(ID < ContentSuggestionsSectionCount);
+    DCHECK(ID < ContentSuggestionsSectionUnknown);
     _ID = ID;
-    _layout = layout;

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

I really find this change weird. You start with great code, and change it to
become okay code. 

[gambard, 2017/02/16 13:45:53]

Can we have your opinion on this marq@?

[marq (ping after 24h), 2017/02/17 13:54:13]

I'm fine with the change.

-    _emptyCell = emptyCell;
-    _title = [title copy];
   }
   return self;
 }
 
 @end