Wireup SafeBrowsingNavigationObserverManager to help PPAPI download attribution

chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc

Index: chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc
diff --git a/chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc b/chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc
index 45207a1c0a7de7bb4cc8afe044b905676e930f97..c621d8646ba7f5f3b369aefc720316f937644690 100644
--- a/chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc
@@ -42,6 +42,28 @@ bool IsEventExpired(const base::Time& event_time, double ttl_in_second) {
   return current_time_in_second - event_time_in_second > ttl_in_second;
 }
 
+// Helper function to determine if the URL type should be LANDING_REFERRER or
+// LANDING_PAGE, and modify AttributionResult accordingly.
+ReferrerChainEntry::URLType GetURLTypeAndAdjustAttributionResult(
+    bool at_user_gesture_limit,
+    SafeBrowsingNavigationObserverManager::AttributionResult* out_result) {
+  // Landing page of a download refers to the page user directly interacts
+  // with to trigger this download (e.g. clicking on download button). Landing
+  // referrer page is the one user interacts with right before navigating to
+  // the landing page.
+  // Since we are tracing navigations backwards, if we've reached
+  // user gesture limit before this navigation event, this is a navigation
+  // leading to the landing referrer page, otherwise it leads to landing page.
+  if (at_user_gesture_limit) {
+    *out_result =
+        SafeBrowsingNavigationObserverManager::SUCCESS_LANDING_REFERRER;
+    return ReferrerChainEntry::LANDING_REFERRER;
+  } else {
+    *out_result = SafeBrowsingNavigationObserverManager::SUCCESS_LANDING_PAGE;
+    return ReferrerChainEntry::LANDING_PAGE;
+  }
+}
+
 }  // namespace
 
 // The expiration period of a user gesture. Any user gesture that happened 1.0
@@ -122,6 +144,18 @@ void SafeBrowsingNavigationObserverManager::OnUserGestureConsumed(
     user_gesture_map_.erase(it);
 }
 
+bool SafeBrowsingNavigationObserverManager::HasUserGesture(
+    content::WebContents* web_contents) {
+  if (!web_contents)
+    return false;
+  auto it = user_gesture_map_.find(web_contents);
+  if (it != user_gesture_map_.end() &&
+      !IsEventExpired(it->second, kUserGestureTTLInSecond)) {
+    return true;
+  }
+  return false;
+}
+
 void SafeBrowsingNavigationObserverManager::RecordHostToIpMapping(
     const std::string& host,
     const std::string& ip) {
@@ -156,7 +190,7 @@ void SafeBrowsingNavigationObserverManager::CleanUpStaleNavigationFootprints() {
 }
 
 SafeBrowsingNavigationObserverManager::AttributionResult
-SafeBrowsingNavigationObserverManager::IdentifyReferrerChain(
+SafeBrowsingNavigationObserverManager::IdentifyReferrerChainForDownload(
     const GURL& target_url,
     int target_tab_id,
     int user_gesture_count_limit,
@@ -172,65 +206,60 @@ SafeBrowsingNavigationObserverManager::IdentifyReferrerChain(
     // We cannot find a single navigation event related to this download.
     return NAVIGATION_EVENT_NOT_FOUND;
   }
-
+  AttributionResult result = SUCCESS;
   AddToReferrerChain(out_referrer_chain, nav_event,
                      ReferrerChainEntry::DOWNLOAD_URL);
-  AttributionResult result = SUCCESS;
   int user_gesture_count = 0;
-  while (user_gesture_count < user_gesture_count_limit) {
-    // Back trace to the next nav_event that was initiated by the user.
-    while (!nav_event->is_user_initiated) {
-      nav_event =
-          FindNavigationEvent(nav_event->source_url,
-                              nav_event->source_main_frame_url,
-                              nav_event->source_tab_id);
-      if (!nav_event)
-        return result;
-      AddToReferrerChain(out_referrer_chain, nav_event,
-                         nav_event->has_server_redirect
-                             ? ReferrerChainEntry::SERVER_REDIRECT
-                             : ReferrerChainEntry::CLIENT_REDIRECT);
-    }
+  GetRemainingReferrerChain(
+      nav_event,
+      user_gesture_count,
+      user_gesture_count_limit,
+      out_referrer_chain,
+      &result);
+  return result;
+}
 
-    user_gesture_count++;
+SafeBrowsingNavigationObserverManager::AttributionResult
+SafeBrowsingNavigationObserverManager::IdentifyReferrerChainForPPAPIDownload(
+    const GURL& initiating_frame_url,
+    int tab_id,
+    bool has_user_gesture,
+    int user_gesture_count_limit,
+    std::vector<ReferrerChainEntry>* out_referrer_chain) {
+  if (!initiating_frame_url.is_valid())
+    return INVALID_URL;
 
-    // If the source_url and source_main_frame_url of current navigation event
-    // are empty, and is_user_initiated is true, this is a browser initiated
-    // navigation (e.g. trigged by typing in address bar, clicking on bookmark,
-    // etc). We reached the end of the referrer chain.
-    if (nav_event->source_url.is_empty() &&
-        nav_event->source_main_frame_url.is_empty()) {
-      DCHECK(nav_event->is_user_initiated);
-      return result;
-    }
+  NavigationEvent* nav_event =
+      FindNavigationEvent(initiating_frame_url, GURL(), tab_id);
+  if (!nav_event) {
+    // We cannot find a single navigation event related to this download.
+    return NAVIGATION_EVENT_NOT_FOUND;
+  }
 
-    nav_event =
-        FindNavigationEvent(nav_event->source_url,
-                            nav_event->source_main_frame_url,
-                            nav_event->source_tab_id);
-    if (!nav_event)
-      return result;
-
-    // Landing page of a download refers to the page user directly interacts
-    // with to trigger this download (e.g. clicking on download button). Landing
-    // referrer page is the one user interacts with right before navigating to
-    // the landing page.
-    // Since we are tracing navigations backwards, if we've encountered 1 user
-    // gesture before this navigation event, this is a navigation leading to the
-    // landing page. If we've encountered 2 user gestures, it leads to landing
-    // referrer page.
-    if (user_gesture_count == 1) {
-      AddToReferrerChain(out_referrer_chain, nav_event,
-                         ReferrerChainEntry::LANDING_PAGE);
-      result = SUCCESS_LANDING_PAGE;
-    } else if (user_gesture_count == 2) {
-      AddToReferrerChain(out_referrer_chain, nav_event,
-                         ReferrerChainEntry::LANDING_REFERRER);
-      result = SUCCESS_LANDING_REFERRER;
-    } else {
-      NOTREACHED();
-    }
+  AttributionResult result = SUCCESS;
+
+  int user_gesture_count = 0;
+  // If this initiating_frame has user gesture, we consider this as the landing
+  // page of the PPAPI download.
+  if (has_user_gesture) {
+    user_gesture_count = 1;
+    AddToReferrerChain(out_referrer_chain, nav_event,
+                       GetURLTypeAndAdjustAttributionResult(
+                          user_gesture_count == user_gesture_count_limit,
+                          &result));
+  } else {
+    AddToReferrerChain(out_referrer_chain, nav_event,
+                       nav_event->has_server_redirect
+                           ? ReferrerChainEntry::SERVER_REDIRECT
+                           : ReferrerChainEntry::CLIENT_REDIRECT);
   }
+
+  GetRemainingReferrerChain(
+      nav_event,
+      user_gesture_count,
+      user_gesture_count_limit,
+      out_referrer_chain,
+      &result);
   return result;
 }
 
@@ -358,17 +387,17 @@ NavigationEvent* SafeBrowsingNavigationObserverManager::FindNavigationEvent(
 
   // If target_url is empty, we should back trace navigation based on its
   // main frame URL instead.
-  const GURL& search_url =
+  GURL search_url =
       target_url.is_empty() ? target_main_frame_url : target_url;
-
   auto it = navigation_map_.find(search_url);
-  if (it == navigation_map_.end()) {
+  if (it == navigation_map_.end())
     return nullptr;
-  }
+
   // Since navigation events are recorded in chronological order, we traverse
   // the vector in reverse order to get the latest match.
   for (auto rit = it->second.rbegin(); rit != it->second.rend(); ++rit) {
     // If tab id is not valid, we only compare url, otherwise we compare both.
+    if (rit->destination_url == search_url)
     if (rit->destination_url == search_url &&
         (target_tab_id == -1 || rit->target_tab_id == target_tab_id)) {
       // If both source_url and source_main_frame_url are empty, and this
@@ -377,7 +406,20 @@ NavigationEvent* SafeBrowsingNavigationObserverManager::FindNavigationEvent(
       // looks for the retargeting navigation event.
       if (rit->source_url.is_empty() && rit->source_main_frame_url.is_empty() &&
           !rit->is_user_initiated) {
-        continue;
+        // If there is a server redirection immediately after retargeting, we
+        // need to adjust our search url to the original request.
+        if (rit->has_server_redirect){
+          NavigationEvent* retargeting_nav_event =
+              FindNavigationEvent(rit->original_request_url,
+                                  GURL(),
+                                  rit->target_tab_id);
+          // Adjust retargeting navigation event's attributes.
+          retargeting_nav_event->has_server_redirect = true;
+          retargeting_nav_event->destination_url = search_url;
+          return retargeting_nav_event;
+        } else {
+          continue;
+        }
       } else {
         return &*rit;
       }
@@ -413,4 +455,54 @@ void SafeBrowsingNavigationObserverManager::AddToReferrerChain(
   referrer_chain->push_back(std::move(referrer_chain_entry));
 }
 
+void SafeBrowsingNavigationObserverManager::GetRemainingReferrerChain(
+    NavigationEvent* last_nav_event_traced,
+    int current_user_gesture_count,
+    int user_gesture_count_limit,
+    std::vector<ReferrerChainEntry>* out_referrer_chain,
+    SafeBrowsingNavigationObserverManager::AttributionResult* out_result) {
+
+  while (current_user_gesture_count < user_gesture_count_limit) {
+    // Back trace to the next nav_event that was initiated by the user.
+    while (!last_nav_event_traced->is_user_initiated) {
+      last_nav_event_traced =
+          FindNavigationEvent(last_nav_event_traced->source_url,
+                              last_nav_event_traced->source_main_frame_url,
+                              last_nav_event_traced->source_tab_id);
+      if (!last_nav_event_traced)
+        return;
+      AddToReferrerChain(out_referrer_chain, last_nav_event_traced,
+                         last_nav_event_traced->has_server_redirect
+                             ? ReferrerChainEntry::SERVER_REDIRECT
+                             : ReferrerChainEntry::CLIENT_REDIRECT);
+    }
+
+    current_user_gesture_count++;
+
+
+    // If the source_url and source_main_frame_url of current navigation event
+    // are empty, and is_user_initiated is true, this is a browser initiated
+    // navigation (e.g. trigged by typing in address bar, clicking on bookmark,
+    // etc). We reached the end of the referrer chain.
+    if (last_nav_event_traced->source_url.is_empty() &&
+        last_nav_event_traced->source_main_frame_url.is_empty()) {
+      DCHECK(last_nav_event_traced->is_user_initiated);
+      return;
+    }
+
+    last_nav_event_traced =
+        FindNavigationEvent(last_nav_event_traced->source_url,
+                            last_nav_event_traced->source_main_frame_url,
+                            last_nav_event_traced->source_tab_id);
+    if (!last_nav_event_traced)
+      return;
+
+    AddToReferrerChain(out_referrer_chain, last_nav_event_traced,
+                       GetURLTypeAndAdjustAttributionResult(
+                          current_user_gesture_count ==
+                              user_gesture_count_limit,
+                          out_result));
+  }
+}
+
 }  // namespace safe_browsing