[DNR] Refactor ActionTracker to use a struct as a key

Bug: 983761
Change-Id: Ic3dd22708d8d20ce2a1cb9a1228835a81681f2ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1935718
Commit-Queue: Kelvin Jiang <kelvinjiang@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719442}

extensions/browser/api/declarative_net_request/action_tracker.cc

@@ -4,6 +4,9 @@
 
 #include "extensions/browser/api/declarative_net_request/action_tracker.h"
 
+#include <tuple>
+#include <utility>
+
 #include "base/stl_util.h"
 #include "base/values.h"
 #include "extensions/browser/api/declarative_net_request/request_action.h"
@@ -47,9 +50,9 @@ void ActionTracker::OnRuleMatched(const RequestAction& request_action,
     return;
 
   const ExtensionId& extension_id = request_action.extension_id;
-  auto key = std::make_pair(extension_id, tab_id);
-  int action_count = ++actions_matched_[key];
+  ExtensionTabIdKey key(extension_id, tab_id);
 
+  size_t action_count = ++actions_matched_[std::move(key)].action_count;
   if (extension_prefs_->GetDNRUseActionCountAsBadgeText(extension_id)) {
     DCHECK(ExtensionsAPIClient::Get());
     ExtensionsAPIClient::Get()->UpdateActionCount(
@@ -62,21 +65,23 @@ void ActionTracker::OnPreferenceEnabled(const ExtensionId& extension_id) const {
   DCHECK(extension_prefs_->GetDNRUseActionCountAsBadgeText(extension_id));
 
   for (auto it = actions_matched_.begin(); it != actions_matched_.end(); ++it) {
-    if (it->first.first != extension_id)
+    const ExtensionTabIdKey& key = it->first;
+    const TrackedInfo& value = it->second;
+
+    if (key.extension_id != extension_id)
       continue;
 
-    int tab_id = it->first.second;
-    int action_count = it->second;
     ExtensionsAPIClient::Get()->UpdateActionCount(
-        browser_context_, extension_id, tab_id, action_count,
+        browser_context_, extension_id, key.tab_id, value.action_count,
         true /* clear_badge_text */);
   }
 }
 
 void ActionTracker::ClearExtensionData(const ExtensionId& extension_id) {
   auto compare_by_extension_id =
-      [&extension_id](const std::pair<ExtensionTabKey, size_t>& it) {
-        return it.first.first == extension_id;
+      [&extension_id](
+          const std::pair<const ExtensionTabIdKey, TrackedInfo>& it) {
+        return it.first.extension_id == extension_id;
       };
 
   base::EraseIf(actions_matched_, compare_by_extension_id);
@@ -84,22 +89,24 @@ void ActionTracker::ClearExtensionData(const ExtensionId& extension_id) {
 
 void ActionTracker::ClearTabData(int tab_id) {
   auto compare_by_tab_id =
-      [&tab_id](const std::pair<ExtensionTabKey, size_t>& it) {
-        return it.first.second == tab_id;
+      [&tab_id](const std::pair<const ExtensionTabIdKey, TrackedInfo>& it) {
+        return it.first.tab_id == tab_id;
       };
 
   base::EraseIf(actions_matched_, compare_by_tab_id);
 }
 
 void ActionTracker::ResetActionCountForTab(int tab_id) {
+  DCHECK_NE(tab_id, extension_misc::kUnknownTabId);
+
   RulesMonitorService* rules_monitor_service =
       RulesMonitorService::Get(browser_context_);
 
   DCHECK(rules_monitor_service);
   for (const auto& extension_id :
        rules_monitor_service->extensions_with_rulesets()) {
-    auto key = std::make_pair(extension_id, tab_id);
-    actions_matched_[key] = 0;
+    ExtensionTabIdKey key(extension_id, tab_id);
+    actions_matched_[std::move(key)].action_count = 0;
 
     if (extension_prefs_->GetDNRUseActionCountAsBadgeText(extension_id)) {
       DCHECK(ExtensionsAPIClient::Get());
@@ -110,6 +117,22 @@ void ActionTracker::ResetActionCountForTab(int tab_id) {
   }
 }
 
+ActionTracker::ExtensionTabIdKey::ExtensionTabIdKey(ExtensionId extension_id,
+                                                    int tab_id)
+    : extension_id(std::move(extension_id)), tab_id(tab_id) {}
+
+ActionTracker::ExtensionTabIdKey::ExtensionTabIdKey(
+    ActionTracker::ExtensionTabIdKey&&) = default;
+
+ActionTracker::ExtensionTabIdKey& ActionTracker::ExtensionTabIdKey::operator=(
+    ActionTracker::ExtensionTabIdKey&&) = default;
+
+bool ActionTracker::ExtensionTabIdKey::operator<(
+    const ExtensionTabIdKey& other) const {
+  return std::tie(tab_id, extension_id) <
+         std::tie(other.tab_id, other.extension_id);
+}
+
 void ActionTracker::DispatchOnRuleMatchedDebugIfNeeded(
     const RequestAction& request_action,
     dnr_api::RequestDetails request_details) {

extensions/browser/api/declarative_net_request/action_tracker.h

@@ -8,7 +8,6 @@
 #include <map>
 #include <vector>
 
-#include "base/macros.h"
 #include "extensions/common/api/declarative_net_request.h"
 #include "extensions/common/extension_id.h"
 
@@ -28,6 +27,8 @@ class ActionTracker {
  public:
   explicit ActionTracker(content::BrowserContext* browser_context);
   ~ActionTracker();
+  ActionTracker(const ActionTracker& other) = delete;
+  ActionTracker& operator=(const ActionTracker& other) = delete;
 
   // Called whenever a request matches with a rule.
   void OnRuleMatched(const RequestAction& request_action,
@@ -53,23 +54,37 @@ class ActionTracker {
   void ResetActionCountForTab(int tab_id);
 
  private:
+  struct ExtensionTabIdKey {
+    ExtensionTabIdKey(ExtensionId extension_id, int tab_id);
+    ExtensionTabIdKey(const ExtensionTabIdKey& other) = delete;
+    ExtensionTabIdKey& operator=(const ExtensionTabIdKey& other) = delete;
+    ExtensionTabIdKey(ExtensionTabIdKey&&);
+    ExtensionTabIdKey& operator=(ExtensionTabIdKey&&);
+
+    ExtensionId extension_id;
+    int tab_id;
+
+    bool operator<(const ExtensionTabIdKey& other) const;
+  };
+
+  // Info tracked for each ExtensionTabIdKey.
+  struct TrackedInfo {
+    size_t action_count = 0;
+  };
+
   // Called from OnRuleMatched. Dispatches a OnRuleMatchedDebug event to the
   // observer for the extension specified by |request_action.extension_id|.
   void DispatchOnRuleMatchedDebugIfNeeded(
       const RequestAction& request_action,
       api::declarative_net_request::RequestDetails request_details);
 
-  using ExtensionTabKey = std::pair<ExtensionId, int>;
-
   // Maps a pair of (extension ID, tab ID) to the number of actions matched for
   // the extension and tab specified.
-  std::map<ExtensionTabKey, int> actions_matched_;
+  std::map<ExtensionTabIdKey, TrackedInfo> actions_matched_;
 
   content::BrowserContext* browser_context_;
 
   ExtensionPrefs* extension_prefs_;
-
-  DISALLOW_COPY_AND_ASSIGN(ActionTracker);
 };
 
 }  // namespace declarative_net_request