Generalize the usage of referrer chain

chrome/browser/safe_browsing/download_protection_service.cc

Index: chrome/browser/safe_browsing/download_protection_service.cc
diff --git a/chrome/browser/safe_browsing/download_protection_service.cc b/chrome/browser/safe_browsing/download_protection_service.cc
index 1a199a0345a395e9bef994dce1f36679f3110b9c..9773f0646e4b97dbeca828f2d66f17d1fd02872b 100644
--- a/chrome/browser/safe_browsing/download_protection_service.cc
+++ b/chrome/browser/safe_browsing/download_protection_service.cc
@@ -1880,10 +1880,8 @@ std::unique_ptr<ReferrerChain> DownloadProtectionService::IdentifyReferrerChain(
       download_tab_id == -1);
   // We look for the referrer chain that leads to the download url first.
   SafeBrowsingNavigationObserverManager::AttributionResult result =
-      navigation_observer_manager_->IdentifyReferrerChainForDownload(
-          download_url,
-          download_tab_id,
-          kDownloadAttributionUserGestureLimit,
+      navigation_observer_manager_->IdentifyReferrerChainByEventURL(
+          download_url, download_tab_id, kDownloadAttributionUserGestureLimit,
           referrer_chain.get());
 
   // If no navigation event is found, this download is not triggered by regular
@@ -1892,10 +1890,9 @@ std::unique_ptr<ReferrerChain> DownloadProtectionService::IdentifyReferrerChain(
   if (result ==
           SafeBrowsingNavigationObserverManager::NAVIGATION_EVENT_NOT_FOUND &&
       web_contents && web_contents->GetLastCommittedURL().is_valid()) {
-    result =
-        navigation_observer_manager_->IdentifyReferrerChainByDownloadWebContent(
-            web_contents, kDownloadAttributionUserGestureLimit,
-            referrer_chain.get());
+    result = navigation_observer_manager_->IdentifyReferrerChainByWebContents(
+        web_contents, kDownloadAttributionUserGestureLimit,
+        referrer_chain.get());
   }
 
   UMA_HISTOGRAM_COUNTS_100(
@@ -1923,7 +1920,7 @@ void DownloadProtectionService::AddReferrerChainToPPAPIClientDownloadRequest(
       "SafeBrowsing.ReferrerHasInvalidTabID.DownloadAttribution",
       tab_id == -1);
   SafeBrowsingNavigationObserverManager::AttributionResult result =
-      navigation_observer_manager_->IdentifyReferrerChainForDownloadHostingPage(
+      navigation_observer_manager_->IdentifyReferrerChainByHostingPage(
           initiating_frame_url, initiating_main_frame_url, tab_id,
           has_user_gesture, kDownloadAttributionUserGestureLimit,
           out_request->mutable_referrer_chain());