Skip clean up if stored RealTimeUrlCheck verdict count is 0.

In incognito mode, the stored verdict count is always 0 because real
time URL check is disabled. Therefore,
CleanUpExpiredRealTimeUrlCheckVerdicts can return early to avoid the
jank.

Bug: 1095078
Change-Id: Ic6c8a5ee441d18cd26e4591186699a7597c158fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404743
Commit-Queue: Xinghui Lu <xinghuilu@chromium.org>
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805991}

components/safe_browsing/core/verdict_cache_manager.cc

@@ -617,6 +617,9 @@ void VerdictCacheManager::CleanUpExpiredPhishGuardVerdicts() {
 }
 
 void VerdictCacheManager::CleanUpExpiredRealTimeUrlCheckVerdicts() {
+  if (stored_verdict_count_real_time_url_check_ == 0) {
+    return;
+  }
   ContentSettingsForOneType safe_browsing_url_check_data_settings;
   content_settings_->GetSettingsForOneType(
       ContentSettingsType::SAFE_BROWSING_URL_CHECK_DATA, std::string(),

components/safe_browsing/core/verdict_cache_manager.h

@@ -149,7 +149,7 @@ class VerdictCacheManager : public history::HistoryServiceObserver,
   base::Optional<size_t> stored_verdict_count_password_entry_;
 
   // Number of verdict stored for this profile for real time url check pings.
-  // This is only used for testing and logging metrics.
+  // This is used for testing, logging metrics and cleaning up during shutdown.
   int stored_verdict_count_real_time_url_check_ = 0;
 
   ScopedObserver<history::HistoryService, history::HistoryServiceObserver>

components/safe_browsing/core/verdict_cache_manager_unittest.cc

@@ -326,6 +326,9 @@ TEST_F(VerdictCacheManagerTest, TestCleanUpExpiredVerdict) {
   ASSERT_EQ(2u, cache_manager_->GetStoredPhishGuardVerdictCount(
                     LoginReputationClientRequest::UNFAMILIAR_LOGIN_PAGE));
 
+  // Prepare 2 verdicts for SAFE_BROWSING_URL_CHECK_DATA:
+  // (1) "www.example.com/" expired
+  // (2) "www.example.com/path" valid
   RTLookupResponse response;
   AddThreatInfoToResponse(response, RTLookupResponse::ThreatInfo::DANGEROUS,
                           RTLookupResponse::ThreatInfo::SOCIAL_ENGINEERING, 0,
@@ -388,6 +391,18 @@ TEST_F(VerdictCacheManagerTest, TestCleanUpExpiredVerdict) {
                 GURL("https://bar.com/xyz/index.jsp"),
                 LoginReputationClientRequest::UNFAMILIAR_LOGIN_PAGE,
                 password_type, &actual_verdict));
+
+  RTLookupResponse::ThreatInfo actual_real_time_threat_info;
+  // No cached SAFE_BROWSING_URL_CHECK_DATA verdict for www.example.com/.
+  EXPECT_EQ(
+      RTLookupResponse::ThreatInfo::VERDICT_TYPE_UNSPECIFIED,
+      cache_manager_->GetCachedRealTimeUrlVerdict(
+          GURL("https://www.example.com/"), &actual_real_time_threat_info));
+  // Has cached SAFE_BROWSING_URL_CHECK_DATA verdict for www.example.com/path.
+  EXPECT_EQ(
+      RTLookupResponse::ThreatInfo::DANGEROUS,
+      cache_manager_->GetCachedRealTimeUrlVerdict(
+          GURL("https://www.example.com/path"), &actual_real_time_threat_info));
 }
 
 TEST_F(VerdictCacheManagerTest, TestCleanUpExpiredVerdictWithInvalidEntry) {