First experimental implementation of the Clear-Site-Data header

content/browser/browsing_data/clear_site_data_throttle.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_THROTTLE_H_
+#define CONTENT_BROWSER_BROWSING_DATA_CLEAR_SITE_DATA_THROTTLE_H_
+
+#include <memory>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/values.h"
+#include "content/public/browser/navigation_throttle.h"
+#include "content/public/browser/resource_request_info.h"
+#include "content/public/browser/web_contents_observer.h"
+
+class Profile;
+
+namespace content {
+
+class NavigationHandle;
+
+// This throttle asynchronously executes the clearing of browsing data.
+// It does not block navigation.

[Mike West, 2016/06/02 07:00:08]

Aside: I think we might need to reconsider this once we see how it works in the
wild. I suspect the race conditions will be super-annoying, and that it might be
preferable to delay the navigation.

[msramek, 2016/06/14 20:12:08]

Agreed. I have no idea right now which one is the right thing to do, so I would
try to gather a few real-life customers first and judge by their experience.

We should definitely start with the non-blocking version though, as the blocking
one might need some UI to explain why the page is unresponsive (I heard we do
that with the webRequest API?).

+class CONTENT_EXPORT ClearSiteDataThrottle : public NavigationThrottle,
+                                             public WebContentsObserver {
+ public:
+  static std::unique_ptr<NavigationThrottle>
+      CreateThrottleFor(NavigationHandle* handle);
+
+  ~ClearSiteDataThrottle() override;
+
+  // WebContentsObserver implementation:
+  void DidFinishNavigation(NavigationHandle* handle) override;
+
+  // NavigationThrottle implementation:
+  ThrottleCheckResult WillProcessResponse() override;
+
+ private:
+  friend class ClearSiteDataThrottleTest;
+
+  struct ConsoleMessage {
+    std::string text;
+    bool error;
+  };
+
+  explicit ClearSiteDataThrottle(NavigationHandle* handle);
+
+  // Parses the value of the 'Clear-Site-Data' header and outputs whether
+  // the header requests to |clear_cookies|, |clear_storage|, and |clear_cache|.
+  // Returns true if parsing was successful.
+  bool ParseHeader(const std::string& header,
+                   bool* clear_cookies, bool* clear_storage, bool* clear_cache);
+
+  // Console logging.
+  void ConsoleLog(const std::string& text, bool error);
+
+  // Cached console messages to be output when the navigation is ready
+  // to commit.
+  std::vector<ConsoleMessage> messages_;
+
+  DISALLOW_COPY_AND_ASSIGN(ClearSiteDataThrottle);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BROWSING_DATA_CLEAR_SITE_DATA_THROTTLE_H_