Add throttling to permission reporter

chrome/browser/safe_browsing/permission_reporter.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_SAFE_BROWSING_PERMISSION_REPORTER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_PERMISSION_REPORTER_H_
 
+#include <queue>
 #include <string>
+#include <unordered_map>
 
+#include "base/time/time.h"
 #include "chrome/browser/permissions/permission_uma_util.h"
 #include "url/gurl.h"
 
+namespace base {
+class Clock;
+}  // namespace base
+
 namespace net {
 class ReportSender;
 class URLRequestContext;
 }  // namespace net
 
 namespace safe_browsing {
 
+struct PermissionAndOrigin {
+  bool operator==(const PermissionAndOrigin& other) const;
+
+  content::PermissionType permission;
+  GURL origin;
+};
+
+struct PermissionAndOriginHash {
+  std::size_t operator()(
+      const PermissionAndOrigin& permission_and_origin) const;

[Nathan Parker, 2016/07/14 22:00:24]

Rather than defining this in the .h file, can you have it use the default
hasher, and then define std::hash<PermissionAndOrigin> in the .cc file?  That'd
avoid extra stuff in the .h file.  If that doesn't work, then you can leave it
here.

[stefanocs, 2016/07/15 02:04:29]

This doesn't seem to work.

I added this:

namespace std {
template <>
struct hash<safe_browsing::PermissionAndOrigin> {
 public:
  std::size_t operator()(const safe_browsing::PermissionAndOrigin&
permission_and_origin) const {
    std::size_t permission_hash =
        static_cast<std::size_t>(permission_and_origin.permission);
    std::size_t origin_hash =
        std::hash<std::string>()(permission_and_origin.origin.spec());
    return base::HashInts(permission_hash, origin_hash);
  }
};

But I was getting CE.

[Nathan Parker, 2016/07/15 23:39:40]

I was thinking

std::size_t
std::hash<safe_browsing::PermissionAndOrigin>(safe_browsing::PermissionAndOrigin
o) {
..
}

(not sure if the <..> is required).  Then no struct is required.  Maybe that
doesn't work.

[stefanocs, 2016/07/18 06:06:17]

Hmmm, that doesn't seem to work. It complains about "template specialization
requires 'template<>'" and then "no function template matches function template
specialization 'hash'".

+};
+
 // Provides functionality for building and serializing reports about permissions
 // to a report collection server.
 class PermissionReporter {
  public:
   // Creates a permission reporter that will send permission reports to
   // the SafeBrowsing permission action server, using |request_context| as the
   // context for the reports.
   explicit PermissionReporter(net::URLRequestContext* request_context);
 
   ~PermissionReporter();
 
   // Sends a serialized permission report to the report collection server.
   // The permission report includes |origin| as the origin of
   // the site requesting permission, |permission| as the type of permission
   // requested, and |action| as the action taken. The report will be serialized
   // using protobuf defined in
   // //src/chrome/common/safe_browsing/permission_report.proto
   void SendReport(const GURL& origin,
                   content::PermissionType permission,
                   PermissionAction action);
 
  private:
   friend class PermissionReporterTest;
 
   // Used by tests. This constructor allows tests to have access to the
-  // ReportSender.
-  explicit PermissionReporter(std::unique_ptr<net::ReportSender> report_sender);
+  // ReportSender and use a test Clock.
+  PermissionReporter(std::unique_ptr<net::ReportSender> report_sender,
+                     std::unique_ptr<base::Clock> clock);
 
   // Builds and serializes a permission report with |origin| as the origin of
   // the site requesting permission, |permission| as the type of permission
   // requested, and |action| as the action taken. The serialized report is
   // written into |output|. Returns true if the serialization was successful and
   // false otherwise.
   static bool BuildReport(const GURL& origin,
                           content::PermissionType permission,
                           PermissionAction action,
                           std::string* output);
 
+  // Returns false if the number of reports sent in the last one minute per
+  // origin per permission is under a threshold, otherwise true.
+  bool IsReportThresholdExceeded(content::PermissionType permission,
+                                 const GURL& origin);
+
   std::unique_ptr<net::ReportSender> permission_report_sender_;
 
+  std::unordered_map<PermissionAndOrigin,
+                     std::queue<base::Time>,
+                     PermissionAndOriginHash>
+      sent_histories;

[Nathan Parker, 2016/07/14 22:00:24]

Should end in underscore.
How about report_log_?  or report_history_.  Or what you have, I'm not picky.

[stefanocs, 2016/07/15 02:04:29]

Done.

+
+  std::unique_ptr<base::Clock> clock_;
+
   DISALLOW_COPY_AND_ASSIGN(PermissionReporter);
 };
 
 }  // namespace safe_browsing
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_PERMISSION_REPORTER_H_