[ios] Plumb SnapshotCache into tab grid.

ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h

Index: ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h
diff --git a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h
index 907f4b9923409c1d9d61183ad9c20b011d630f3b..643b890f37debee842f40d89ce33e6ae36212301 100644
--- a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h
+++ b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h
@@ -9,6 +9,8 @@
 
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_consumer.h"
 
+@class SnapshotCache;
+
 // Controller for a scrolling view displaying square cells that represent
 // the user's open tabs.
 @interface TabCollectionViewController
@@ -18,6 +20,8 @@
 // Model for collection view.
 @property(nonatomic, strong, readonly)
     NSMutableArray<TabCollectionItem*>* items;
+// Cache used to retrieve snapshot images for tab cells.
+@property(nonatomic, weak) SnapshotCache* snapshotCache;
 @end
 
 #endif  // IOS_CLEAN_CHROME_BROWSER_UI_TAB_COLLECTION_TAB_COLLECTION_VIEW_CONTROLLER_H_