Add throttling to permission reporter

chrome/browser/safe_browsing/permission_reporter.cc

Index: chrome/browser/safe_browsing/permission_reporter.cc
diff --git a/chrome/browser/safe_browsing/permission_reporter.cc b/chrome/browser/safe_browsing/permission_reporter.cc
index b64f60ceff6ea32b265873919d5740b8253b4819..7478e0b7a59fb55fd2585eee1ba41a15b655db9d 100644
--- a/chrome/browser/safe_browsing/permission_reporter.cc
+++ b/chrome/browser/safe_browsing/permission_reporter.cc
@@ -2,8 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/memory/ptr_util.h"
 #include "chrome/browser/safe_browsing/permission_reporter.h"
+
+#include <functional>
+
+#include "base/hash.h"
+#include "base/memory/ptr_util.h"
 #include "chrome/common/safe_browsing/permission_report.pb.h"
 #include "content/public/browser/permission_type.h"
 #include "net/url_request/report_sender.h"
@@ -18,6 +22,8 @@ const char kPermissionActionReportingUploadUrl[] =
     "http://safebrowsing.googleusercontent.com/safebrowsing/clientreport/"
     "permission-action";
 
+const int kMaximumReportsPerOriginPerPermission = 5;

[raymes, 2016/06/27 06:26:56]

...PerMinute?

[stefanocs, 2016/06/27 07:34:57]

Done.

+
 PermissionReport::PermissionType PermissionTypeForReport(
     PermissionType permission) {
   switch (permission) {
@@ -74,6 +80,19 @@ PermissionReport::Action PermissionActionForReport(PermissionAction action) {
 
 }  // namespace
 
+bool PermissionAndOrigin::operator==(const PermissionAndOrigin& other) const {
+  return (permission == other.permission && origin == other.origin);
+}
+
+std::size_t PermissionAndOriginHash::operator()(
+    const 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);
+}
+
 PermissionReporter::PermissionReporter(net::URLRequestContext* request_context)
     : PermissionReporter(base::WrapUnique(new net::ReportSender(
           request_context,
@@ -88,6 +107,8 @@ PermissionReporter::~PermissionReporter() {}
 void PermissionReporter::SendReport(const GURL& origin,
                                     content::PermissionType permission,
                                     PermissionAction action) {
+  if (!IsAllowedToSend(permission, origin))
+    return;
   std::string serialized_report;
   BuildReport(origin, permission, action, &serialized_report);
   permission_report_sender_->Send(GURL(kPermissionActionReportingUploadUrl),
@@ -108,4 +129,20 @@ bool PermissionReporter::BuildReport(const GURL& origin,
   return report.SerializeToString(output);
 }
 
+bool PermissionReporter::IsAllowedToSend(content::PermissionType permission,
+                                         const GURL& origin) {
+  std::queue<base::Time>& history = sent_histories[{permission, origin}];
+  base::Time current_time = base::Time::Now();
+  // Remove entries that are sent more than one minute ago.
+  while (!history.empty() &&
+         current_time - history.front() > base::TimeDelta::FromMinutes(1))
+    history.pop();
+  if (history.size() < kMaximumReportsPerOriginPerPermission) {
+    history.push(current_time);
+    return true;
+  } else {
+    return false;
+  }
+}
+
 }  // namespace safe_browsing