Remove all ReadingList entries on managed account signout.

ios/chrome/browser/signin/browser_state_data_remover.h

Index: ios/chrome/browser/signin/browser_state_data_remover.h
diff --git a/ios/chrome/browser/signin/browser_state_data_remover.h b/ios/chrome/browser/signin/browser_state_data_remover.h
index fc5f2a31787d002fad1c9b065c81d8665ad6f952..69024243464c2ee34b6fcd085bb0484ed2ebe01d 100644
--- a/ios/chrome/browser/signin/browser_state_data_remover.h
+++ b/ios/chrome/browser/signin/browser_state_data_remover.h
@@ -13,6 +13,10 @@ namespace ios {
 class ChromeBrowserState;
 }
 
+namespace reading_list {
+class ReadingListRemoverHelper;
+}
+
 // Helper that wipes all the data in the given browser state. This deletes all
 // browsing data and all the bookmarks.
 class BrowserStateDataRemover {
@@ -38,10 +42,15 @@ class BrowserStateDataRemover {
  private:
   void NotifyWithDetails(
       const IOSChromeBrowsingDataRemover::NotificationDetails& details);
+  void ReadingListCleaned(
+      const IOSChromeBrowsingDataRemover::NotificationDetails& details,
+      bool reading_list_cleaned);
 
   ios::ChromeBrowserState* browser_state_;
   base::scoped_nsprotocol<ProceduralBlock> callback_;
   IOSChromeBrowsingDataRemover::CallbackSubscription callback_subscription_;
+  std::unique_ptr<reading_list::ReadingListRemoverHelper>
+      reading_list_remover_helper_;
   bool forget_last_username_;
 };