Wire up download attribution enable finch experiment

chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_NAVIGATION_OBSERVER_MANAGER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_NAVIGATION_OBSERVER_MANAGER_H_
 
+#include "base/feature_list.h"
 #include "chrome/common/safe_browsing/csd.pb.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "url/gurl.h"
 
+class Profile;
+
 namespace safe_browsing {
 
 class SafeBrowsingNavigationObserver;
 struct NavigationEvent;
 struct ResolvedIPAddress;
 
 // Manager class for SafeBrowsingNavigationObserver, which is in charge of
 // cleaning up stale navigation events, and identifying landing page/landing
 // referrer for a specific download.
 // TODO(jialiul): For now, SafeBrowsingNavigationObserverManager also listens to
 // NOTIFICATION_RETARGETING as a way to detect cross frame/tab navigation.
 // Remove base class content::NotificationObserver when
 // WebContentsObserver::DidOpenRequestedURL() covers all retargeting cases.
 class SafeBrowsingNavigationObserverManager
     : public content::NotificationObserver,
       public base::RefCountedThreadSafe<SafeBrowsingNavigationObserverManager> {
  public:
+  static const base::Feature kDownloadAttribution;
+
   // For UMA histogram counting. Do NOT change order.
   enum AttributionResult {
     SUCCESS = 1,                   // Identified referrer chain is not empty.
     SUCCESS_LANDING_PAGE = 2,      // Successfully identified landing page.
     SUCCESS_LANDING_REFERRER = 3,  // Successfully identified landing referrer.
     INVALID_URL = 4,
     NAVIGATION_EVENT_NOT_FOUND = 5,
 
     // Always at the end.
     ATTRIBUTION_FAILURE_TYPE_MAX
   };
 
   // Helper function to check if user gesture is older than
   // kUserGestureTTLInSecond.
   static bool IsUserGestureExpired(const base::Time& timestamp);
+
   // Helper function to strip empty ref fragment from a URL. Many pages
   // end up with a "#" at the end of their URLs due to navigation triggered by
   // href="#" and javascript onclick function. We don't want to have separate
   // entries for these cases in the maps.
   static GURL ClearEmptyRef(const GURL& url);
 
+  // Checks if we should enable observing navigations for safe browsing purpose.
+  // Return true if the safe browsing service and the download attribution
+  // feature are both enabled, and safe browsing service is initialized.
+  static bool IsEnabledAndReady(Profile* profile);
+
   SafeBrowsingNavigationObserverManager();
 
   // Add |nav_event| to |navigation_map_| based on |nav_event_key|. Object
   // pointed to by |nav_event| will be no longer accessible after this function.
   void RecordNavigationEvent(const GURL& nav_event_key,
                              NavigationEvent* nav_event);
   void RecordUserGestureForWebContents(content::WebContents* web_contents,
                                        const base::Time& timestamp);
   void OnUserGestureConsumed(content::WebContents* web_contents,
                              const base::Time& timestamp);
@@ skipping 11 matching lines @@
   // leading to the target, with the coverage limited to
   // |user_gesture_count_limit| number of user gestures. Then convert these
   // identified NavigationEvents into ReferrerChainEntrys and append them to
   // |out_referrer_chain|.
   AttributionResult IdentifyReferrerChain(
       const GURL& target_url,
       int target_tab_id,  // -1 if tab id is not valid
       int user_gesture_count_limit,
       std::vector<ReferrerChainEntry>* out_referrer_chain);
 
-  // Identify and add referrer chain info of a download to ClientDownloadRequest
-  // proto. This function also record UMA stats of download attribution result.
-  // TODO(jialiul): This function will be moved to DownloadProtectionService
-  // class shortly.
-  void AddReferrerChainToClientDownloadRequest(
-      const GURL& download_url,
-      content::WebContents* source_contents,
-      ClientDownloadRequest* out_request);
-
  private:
   friend class base::RefCountedThreadSafe<
       SafeBrowsingNavigationObserverManager>;
   friend class TestNavigationObserverManager;
   friend class SBNavigationObserverBrowserTest;
   friend class SBNavigationObserverTest;
 
   struct GurlHash {
     std::size_t operator()(const GURL& url) const {
       return std::hash<std::string>()(url.spec());
@@ skipping 82 matching lines @@
 
   content::NotificationRegistrar registrar_;
 
   base::OneShotTimer cleanup_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(SafeBrowsingNavigationObserverManager);
 };
 }  // namespace safe_browsing
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_NAVIGATION_OBSERVER_MANAGER_H_