Implement deletion of storage per site.

chrome/browser/ui/webui/settings/site_settings_handler.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_SETTINGS_SITE_SETTINGS_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SETTINGS_SITE_SETTINGS_HANDLER_H_
 
 #include <vector>
 
 #include "chrome/browser/storage/storage_info_fetcher.h"
@@ skipping 12 matching lines @@
      : public SettingsPageUIHandler, StorageInfoFetcher::Observer {
  public:
   explicit SiteSettingsHandler(Profile* profile);
   ~SiteSettingsHandler() override;
 
   // SettingsPageUIHandler:
   void RegisterMessages() override;
 
   // StorageInfoFetcher::Observer:
   void OnGetUsageInfo(const storage::UsageInfoEntries& entries) override;
+  void OnUsageInfoCleared(storage::QuotaStatusCode code) override;
 
  private:
   // Asynchronously fetches the usage for a given origin. Replies back with
   // OnGetUsageInfo above.
   void HandleFetchUsageTotal(const base::ListValue* args);
 
+  // Deletes the storage being used for a given host.
+  void HandleClearUsage(const base::ListValue* args);
+
   Profile* profile_;
 
   // The host for which to fetch usage.
   std::string usage_host_;
 
+  // The origin for which to clear usage.
+  std::string clearing_origin_;
+
   // The helper object asynchronously fetching storage info.
   scoped_refptr<StorageInfoFetcher> storage_info_fetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(SiteSettingsHandler);
 };
 
 }  // namespace settings
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_SITE_SETTINGS_HANDLER_H_