[iOS] Hide Tab Grid recently closed section during search when empty

Additionally, remove the Show Full History item when searching because
actions will be added to a new section at the bottom of the table.

Change-Id: I64788695f5c08a1bdf543ff9382f88ebb8fd3edd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3443820
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#969740}

ios/chrome/browser/ui/recent_tabs/recent_tabs_table_view_controller.mm

@@ -223,10 +223,6 @@ typedef std::pair<SessionID, TableViewURLItem*> RecentlyClosedTableViewItemPair;
   }
 }
 
-- (void)viewWillDisappear:(BOOL)animated {
-  [super viewWillDisappear:animated];
-}
-
 #pragma mark - Setters & Getters
 
 - (void)setBrowser:(Browser*)browser {
@@ -318,6 +314,11 @@ typedef std::pair<SessionID, TableViewURLItem*> RecentlyClosedTableViewItemPair;
 #pragma mark Recently Closed Section
 
 - (void)addRecentlyClosedSection {
+  // Hide section during search if empty.
+  if (![self recentlyClosedTabsSectionExists]) {
+    return;
+  }
+
   TableViewModel* model = self.tableViewModel;
 
   // Recently Closed Section.
@@ -341,6 +342,12 @@ typedef std::pair<SessionID, TableViewURLItem*> RecentlyClosedTableViewItemPair;
   // Add Recently Closed Tabs Cells.
   [self addRecentlyClosedTabItems];
 
+  if (self.searchTerms.length) {
+    // Hide the show full history item in the recently closed section while
+    // searching.
+    return;
+  }
+
   // Add show full history item last.
   TableViewImageItem* historyItem =
       [[TableViewImageItem alloc] initWithType:ItemTypeShowFullHistory];
@@ -1158,6 +1165,21 @@ typedef std::pair<SessionID, TableViewURLItem*> RecentlyClosedTableViewItemPair;
 
 #pragma mark - Recently closed tab helpers
 
+- (BOOL)recentlyClosedTabsSectionExists {
+  // Recently closed section always exists when tab search is disabled.
+  if (!IsTabsSearchEnabled()) {
+    return YES;
+  }
+
+  // The recently closed section does not exist if the user is searching and
+  // there are no matching recently closed items.
+  if (self.searchTerms.length && [self numberOfRecentlyClosedTabs] == 0) {
+    return NO;
+  }
+
+  return YES;
+}
+
 - (NSInteger)numberOfRecentlyClosedTabs {
   if (!self.tabRestoreService)
     return 0;