Minor improvements to RecentTabHelper.

chrome/browser/android/offline_pages/recent_tab_helper.h

Index: chrome/browser/android/offline_pages/recent_tab_helper.h
diff --git a/chrome/browser/android/offline_pages/recent_tab_helper.h b/chrome/browser/android/offline_pages/recent_tab_helper.h
index 94c69e4ff1bd586eb30f75bfb41957955e2ebe7a..0095404ee3c2a43a7b3847c7a2b6628a8ec22f81 100644
--- a/chrome/browser/android/offline_pages/recent_tab_helper.h
+++ b/chrome/browser/android/offline_pages/recent_tab_helper.h
@@ -71,23 +71,29 @@ class RecentTabHelper
 
  private:
   // Keeps client_id/request_id that will be used for the offline snapshot.
-  struct DownloadPageInfo {
+  struct SnapshotProgressInfo {
    public:
-    DownloadPageInfo(const ClientId& client_id,
-                     int64_t request_id)
-        : client_id_(client_id),
-          request_id_(request_id),
-          page_snapshot_completed_(false) {}
+    // For a downloads snapshot request, where the |request_id| is defined.
+    SnapshotProgressInfo(const ClientId& client_id, int64_t request_id)
+        : client_id(client_id), request_id(request_id) {}
+
+    // For a last_n snapshot request.
+    explicit SnapshotProgressInfo(const ClientId& client_id)
+        : client_id(client_id) {}
+
+    bool IsForLastN();
 
     // The ClientID to go with the offline page.
-    ClientId client_id_;
+    ClientId client_id;
+
     // Id of the suspended request in Background Offliner. Used to un-suspend
     // the request if the capture of the current page was not possible (e.g.
     // the user navigated to another page before current one was loaded).
-    // 0 if this is a "last_1" info.
-    int64_t request_id_;
+    // 0 if this is a "last_n" info.
+    int64_t request_id = OfflinePageModel::kInvalidOfflineId;
+
     // True if there was at least one snapshot successfully completed.
-    bool page_snapshot_completed_;
+    bool page_snapshot_completed = false;
   };
 
   explicit RecentTabHelper(content::WebContents* web_contents);
@@ -105,19 +111,19 @@ class RecentTabHelper
 
   // Page model is a service, no ownership. Can be null - for example, in
   // case when tab is in incognito profile.
-  OfflinePageModel* page_model_;
+  OfflinePageModel* page_model_ = nullptr;
 
   // If false, never make snapshots off the attached WebContents.
   // Not page-specific.
-  bool snapshots_enabled_;
+  bool snapshots_enabled_ = false;
 
   // Becomes true during navigation if the page is ready for snapshot as
   // indicated by at least one callback from SnapshotController.
-  bool is_page_ready_for_snapshot_;
+  bool is_page_ready_for_snapshot_ = false;
 
   // Info for the offline page to capture. Null if the tab is not capturing
   // current page.
-  std::unique_ptr<DownloadPageInfo> download_info_;
+  std::unique_ptr<SnapshotProgressInfo> snapshot_info_;
 
   // If empty, the tab does not have AndroidId and can not capture pages.
   std::string tab_id_;
@@ -137,4 +143,5 @@ class RecentTabHelper
 };
 
 }  // namespace offline_pages
+
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_RECENT_TAB_HELPER_H_