Upstream Chrome on iOS source code [4/11].

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"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@interface FakeCollectionViewCell : MDCCollectionViewCell
+@end
+
+@implementation FakeCollectionViewCell
+@end
+
+@interface FakeCollectionViewItem : CollectionViewItem
+@property(nonatomic, assign) NSInteger configureCount;
+@end
+@implementation FakeCollectionViewItem
+@synthesize configureCount = _configureCount;
+- (void)configureCell:(MDCCollectionViewCell*)cell {
+  [super configureCell:cell];
+  EXPECT_TRUE([cell isMemberOfClass:[FakeCollectionViewCell class]]);
+  self.configureCount++;
+}
+@end
+
+namespace {
+
+TEST(MDCCollectionViewCellChrome, PreferredHeightCallsConfigureCell) {
+  FakeCollectionViewItem* item =
+      [[FakeCollectionViewItem alloc] initWithType:0];
+  item.cellClass = [FakeCollectionViewCell class];
+  EXPECT_EQ(0, item.configureCount);
+
+  [MDCCollectionViewCell cr_preferredHeightForWidth:0 forItem:item];
+
+  EXPECT_EQ(1, item.configureCount);
+}
+
+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);
+}
+
+}  // namespace