Use MDCTypography instead of MDFRobotoFontLoader directly.

ios/chrome/browser/ui/collection_view/cells/MDCCollectionViewCell+Chrome_unittest.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/collection_view/cells/MDCCollectionViewCell+Chrome.h"
 
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_footer_item.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_item.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 34 matching lines @@
 
 TEST(MDCCollectionViewCellChrome, PreferredHeight) {
   CollectionViewFooterItem* footerItem =
       [[CollectionViewFooterItem alloc] initWithType:0];
   footerItem.text = @"This is a pretty lengthy sentence.";
   CGFloat (^heightForWidth)(CGFloat width) = ^(CGFloat width) {
     return [MDCCollectionViewCell cr_preferredHeightForWidth:width
                                                      forItem:footerItem];
   };
   EXPECT_NEAR(heightForWidth(300), 50, 5);
-  EXPECT_NEAR(heightForWidth(100), 110, 5);
+  EXPECT_NEAR(heightForWidth(100), 115, 5);

[lpromero, 2017/05/31 15:14:48]

With Roboto, heightForWidth(100) returns 114.5. With SanFrancisco, it returns
116. 116 was one too many. I change here the target to 115, as it more closely
match both fonts.

 }
 
 }  // namespace