First experimental implementation of the Clear-Site-Data header

content/browser/browsing_data/clear_site_data_header_observer.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 CONTENT_BROWSER_BROWSING_DATA_CLEAR_SITE_DATA_HEADER_OBSERVER_H_
+#define CONTENT_BROWSER_BROWSING_DATA_CLEAR_SITE_DATA_HEADER_OBSERVER_H_
+
+#include <memory>
+#include <vector>
+
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "base/values.h"
+#include "content/public/browser/resource_request_info.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/common/console_message_level.h"
+#include "url/gurl.h"
+
+namespace content {
+
+class NavigationHandle;
+
+// This observer parses the Clear-Site-Data header and asynchronously executes
+// the clearing of browsing data. See the W3C working draft at
+// https://www.w3.org/TR/clear-site-data/.
+// TODO(msramek): It is currently not clear whether we should defer
+// the navigation until clearing is complete. If we decide that it should,
+// this class should be instead implemented as a NavigationThrottle.
+class CONTENT_EXPORT ClearSiteDataHeaderObserver : public WebContentsObserver {
+ public:
+  struct ConsoleMessage {
+    GURL url;
+    std::string text;
+    ConsoleMessageLevel level;
+  };
+
+  static std::unique_ptr<ClearSiteDataHeaderObserver> CreateFor(
+      NavigationHandle* handle);
+
+  ~ClearSiteDataHeaderObserver() override;
+
+  // WebContentsObserver implementation:
+  void DidStartNavigation(NavigationHandle* handle) override;
+  void DidRedirectNavigation(NavigationHandle* handle) override;
+  void DidFinishNavigation(NavigationHandle* handle) override;
+
+ private:
+  friend class ClearSiteDataHeaderObserverTest;
+  FRIEND_TEST_ALL_PREFIXES(ClearSiteDataHeaderObserverTest, ParseHeader);
+  FRIEND_TEST_ALL_PREFIXES(ClearSiteDataHeaderObserverTest, InvalidHeader);
+
+  explicit ClearSiteDataHeaderObserver(WebContents* web_contents);
+
+  // Scans for 'Clear-Site-Data' headers, calls ParseHeader() to parse them,
+  // and requests the actual data clearing. This is the common logic
+  // of DidFinishNavigation() and DidRedirectNavigation().
+  void HandleHeader(NavigationHandle* navigation_handle);
+
+  // Parses the value of the 'Clear-Site-Data' header and outputs whether
+  // the header requests to |clear_cookies|, |clear_storage|, and |clear_cache|.
+  // The |messages| vector will be filled with messages to be output in the
+  // console. Returns true if parsing was successful.
+  bool ParseHeader(const std::string& header,
+                   bool* clear_cookies,
+                   bool* clear_storage,
+                   bool* clear_cache,
+                   std::vector<ConsoleMessage>* messages);
+
+  // Cached console messages to be output when the RenderFrameHost is ready.
+  std::vector<ConsoleMessage> messages_;
+  GURL current_url_;
+
+  DISALLOW_COPY_AND_ASSIGN(ClearSiteDataHeaderObserver);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BROWSING_DATA_CLEAR_SITE_DATA_HEADER_OBSERVER_H_