[ios] Plumb SnapshotCache into tab grid.

BUG=686770

Review-Url: https://codereview.chromium.org/2971113002
Cr-Commit-Position: refs/heads/master@{#485145}

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_

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

@@ -28,6 +28,7 @@
 @synthesize tabs = _tabs;
 @synthesize items = _items;
 @synthesize selectedIndex = _selectedIndex;
+@synthesize snapshotCache = _snapshotCache;
 
 #pragma mark - UIViewController
 
@@ -118,8 +119,7 @@
   [cell setSessionType:TabSwitcherSessionType::REGULAR_SESSION];
   DCHECK_LE(indexPath.item, INT_MAX);
   int index = static_cast<int>(indexPath.item);
-  // PLACEHOLDER: SnapshotCache will be passed into the cell.
-  [cell configureCell:self.items[index] snapshotCache:nil];
+  [cell configureCell:self.items[index] snapshotCache:self.snapshotCache];
   return cell;
 }
 
@@ -194,8 +194,7 @@
   TabCollectionTabCell* cell = base::mac::ObjCCastStrict<TabCollectionTabCell>(
       [self.tabs cellForItemAtIndexPath:[NSIndexPath indexPathForItem:index
                                                             inSection:0]]);
-  // PLACEHOLDER: SnapshotCache will be passed into the cell.
-  [cell configureCell:self.items[index] snapshotCache:nil];
+  [cell configureCell:self.items[index] snapshotCache:self.snapshotCache];
 }
 
 - (void)populateItems:(NSArray<TabCollectionItem*>*)items

ios/clean/chrome/browser/ui/tab_grid/BUILD.gn

@@ -16,6 +16,7 @@ source_set("tab_grid") {
     ":tab_grid_ui",
     "//base",
     "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/snapshots",
     "//ios/chrome/browser/web_state_list",
     "//ios/clean/chrome/browser",
     "//ios/clean/chrome/browser/ui/commands",

ios/clean/chrome/browser/ui/tab_grid/tab_grid_coordinator.mm

@@ -9,6 +9,7 @@
 #include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#import "ios/chrome/browser/snapshots/snapshot_cache_factory.h"
 #import "ios/chrome/browser/web_state_list/web_state_list.h"
 #import "ios/clean/chrome/browser/ui/commands/context_menu_commands.h"
 #import "ios/clean/chrome/browser/ui/commands/settings_commands.h"
@@ -43,6 +44,7 @@
 @property(nonatomic, weak) TabCoordinator* activeTabCoordinator;
 @property(nonatomic, readonly) WebStateList& webStateList;
 @property(nonatomic, strong) TabGridMediator* mediator;
+@property(nonatomic, readonly) SnapshotCache* snapshotCache;
 @end
 
 @implementation TabGridCoordinator
@@ -58,6 +60,11 @@
   return self.browser->web_state_list();
 }
 
+- (SnapshotCache*)snapshotCache {
+  return SnapshotCacheFactory::GetForBrowserState(
+      self.browser->browser_state());
+}
+
 #pragma mark - BrowserCoordinator
 
 - (void)start {
@@ -71,6 +78,7 @@
 
   self.viewController = [[TabGridViewController alloc] init];
   self.viewController.dispatcher = static_cast<id>(self.browser->dispatcher());
+  self.viewController.snapshotCache = self.snapshotCache;
 
   self.mediator.consumer = self.viewController;