Add throttling to permission reporter

chrome/browser/safe_browsing/permission_reporter.h

Index: chrome/browser/safe_browsing/permission_reporter.h
diff --git a/chrome/browser/safe_browsing/permission_reporter.h b/chrome/browser/safe_browsing/permission_reporter.h
index 523de8e57057aa67d749f31333c690896448f132..2c78887813c9a58d22ccb4a9acf8771f55e26268 100644
--- a/chrome/browser/safe_browsing/permission_reporter.h
+++ b/chrome/browser/safe_browsing/permission_reporter.h
@@ -5,11 +5,18 @@
 #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;
@@ -17,6 +24,18 @@ class URLRequestContext;
 
 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;
+};

[raymes, 2016/06/29 07:09:17]

nit: If we define these as nested classes within PermissionReporter, we can just
forward declare them in the header and have the complexity defined in the cc
file which might be a bit nicer. 

[stefanocs, 2016/06/30 00:24:51]

Do you mean these structs should be forward declared in this header file and
have the declaration and definition in the cc file? That's what I was trying to
do but the hash table needs to know the declaration of these structs in the this
file.

+
 // Provides functionality for building and serializing reports about permissions
 // to a report collection server.
 class PermissionReporter {
@@ -42,8 +61,9 @@ class PermissionReporter {
   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.
+  explicit 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
@@ -55,8 +75,19 @@ class PermissionReporter {
                           PermissionAction action,
                           std::string* output);
 
+  // Returns true if the number of reports sent in the last one minute per
+  // origin per permission is under a threshold, otherwise false.
+  bool IsAllowedToSend(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;

[raymes, 2016/06/29 07:09:17]

It seems like we might need this complexity then unless we change the
definition. Let's get Kendra's thoughts.

[stefanocs, 2016/06/30 00:24:51]

Acknowledged.

+
+  std::unique_ptr<base::Clock> clock_;
+
   DISALLOW_COPY_AND_ASSIGN(PermissionReporter);
 };