Cleanup ContentSuggestions, removing unused functions

ios/chrome/browser/ui/content_suggestions/content_suggestions_text_item.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_item.h"
+#import "ios/chrome/browser/ui/content_suggestions/content_suggestions_text_item.h"
 
-#import "ios/chrome/browser/ui/content_suggestions/content_suggestions_item_actions.h"
+#import "ios/chrome/browser/ui/content_suggestions/content_suggestions_text_item_actions.h"
 #import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-@interface ContentSuggestionsItem ()
+@interface ContentSuggestionsTextItem ()
 
 @property(nonatomic, copy) NSString* title;
 @property(nonatomic, copy) NSString* subtitle;
 
 @end
 
-@implementation ContentSuggestionsItem
+@implementation ContentSuggestionsTextItem
 
 @synthesize title = _title;
 @synthesize subtitle = _subtitle;
 
 - (instancetype)initWithType:(NSInteger)type
                        title:(NSString*)title
                     subtitle:(NSString*)subtitle {
   self = [super initWithType:type];
   if (self) {
-    self.cellClass = [ContentSuggestionsCell class];
+    self.cellClass = [ContentSuggestionsTextCell class];
     _title = [title copy];
     _subtitle = [subtitle copy];
   }
   return self;
 }
 
 #pragma mark - CollectionViewItem
 
-- (void)configureCell:(ContentSuggestionsCell*)cell {
+- (void)configureCell:(ContentSuggestionsTextCell*)cell {
   [super configureCell:cell];
   [cell.titleButton setTitle:self.title forState:UIControlStateNormal];
   cell.detailTextLabel.text = self.subtitle;
 }
 
 @end
 
-#pragma mark - ContentSuggestionsCell
+#pragma mark - ContentSuggestionsTextCell
 
-@implementation ContentSuggestionsCell
+@implementation ContentSuggestionsTextCell
 
 @synthesize titleButton = _titleButton;
 @synthesize detailTextLabel = _detailTextLabel;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     id<MDCTypographyFontLoading> fontLoader = [MDCTypography fontLoader];
     _titleButton = [UIButton buttonWithType:UIButtonTypeSystem];
     _titleButton.titleLabel.font = [fontLoader mediumFontOfSize:16];
     _titleButton.titleLabel.textColor = [[MDCPalette greyPalette] tint900];
     [_titleButton addTarget:nil
-                     action:@selector(addNewItem:)
+                     action:@selector(addNewTextItem:)
            forControlEvents:UIControlEventTouchUpInside];
 
     _detailTextLabel = [[UILabel alloc] init];
     _detailTextLabel.font = [fontLoader mediumFontOfSize:14];
     _detailTextLabel.textColor = [[MDCPalette greyPalette] tint500];
 
     UIStackView* labelsStack = [[UIStackView alloc]
         initWithArrangedSubviews:@[ _titleButton, _detailTextLabel ]];
     labelsStack.axis = UILayoutConstraintAxisVertical;
 
@@ skipping 13 matching lines @@
       [self.contentView.bottomAnchor
           constraintEqualToAnchor:labelsStack.bottomAnchor]
     ]];
 
     self.backgroundColor = [UIColor whiteColor];
   }
   return self;
 }
 
 @end