Reland of [Sync] Put session tracker in charge of maintaining local state.

components/sync_sessions/sessions_sync_manager.h

 // Copyright 2014 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 COMPONENTS_SYNC_SESSIONS_SESSIONS_SYNC_MANAGER_H_
 #define COMPONENTS_SYNC_SESSIONS_SESSIONS_SYNC_MANAGER_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 12 matching lines @@
 #include "components/sync/base/sync_prefs.h"
 #include "components/sync/device_info/device_info.h"
 #include "components/sync/model/syncable_service.h"
 #include "components/sync_sessions/favicon_cache.h"
 #include "components/sync_sessions/local_session_event_router.h"
 #include "components/sync_sessions/lost_navigations_recorder.h"
 #include "components/sync_sessions/open_tabs_ui_delegate.h"
 #include "components/sync_sessions/revisit/page_revisit_broadcaster.h"
 #include "components/sync_sessions/synced_session.h"
 #include "components/sync_sessions/synced_session_tracker.h"
-#include "components/sync_sessions/tab_node_pool.h"
 
 namespace syncer {
 class LocalDeviceInfoProvider;
 class SyncErrorFactory;
 class SyncPrefs;
 }  // namespace syncer
 
 namespace sync_pb {
 class SessionHeader;
 class SessionSpecifics;
@@ skipping 67 matching lines @@
   }
 
   FaviconCache* GetFaviconCache();
 
   // Triggers garbage collection of stale sessions (as defined by
   // |stale_session_threshold_days_|). This is called every time we see new
   // sessions data downloaded (sync cycles complete).
   void DoGarbageCollection();
 
  private:
-  // Keep all the links to local tab data in one place. A tab_node_id and tab
-  // must be passed at creation. The tab_node_id is not mutable, although
-  // all other fields are.
-  class TabLink {
-   public:
-    TabLink(int tab_node_id, const SyncedTabDelegate* tab)
-        : tab_node_id_(tab_node_id), tab_(tab) {}
-
-    void set_tab(const SyncedTabDelegate* tab) { tab_ = tab; }
-    void set_url(const GURL& url) { url_ = url; }
-
-    int tab_node_id() const { return tab_node_id_; }
-    const SyncedTabDelegate* tab() const { return tab_; }
-    const GURL& url() const { return url_; }
-
-   private:
-    // The id for the sync node this tab is stored in.
-    const int tab_node_id_;
-
-    // The tab object itself.
-    const SyncedTabDelegate* tab_;
-
-    // The currently visible url of the tab (used for syncing favicons).
-    GURL url_;
-
-    DISALLOW_COPY_AND_ASSIGN(TabLink);
-  };
-
-  // Container for accessing local tab data by tab id.
-  typedef std::map<SessionID::id_type, linked_ptr<TabLink>> TabLinksMap;
-
   friend class extensions::ExtensionSessionsTest;
   friend class SessionsSyncManagerTest;
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest, PopulateSessionHeader);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest, PopulateSessionWindow);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest, ValidTabs);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest, SetSessionTabFromDelegate);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest,
                            SetSessionTabFromDelegateNavigationIndex);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest,
                            SetSessionTabFromDelegateCurrentInvalid);
@@ skipping 13 matching lines @@
                            CheckPrerenderedWebContentsSwap);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest,
                            AssociateWindowsDontReloadTabs);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest, SwappedOutOnRestore);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest,
                            ProcessRemoteDeleteOfLocalSession);
   FRIEND_TEST_ALL_PREFIXES(SessionsSyncManagerTest, SetVariationIds);
 
   void InitializeCurrentMachineTag(const std::string& cache_guid);
 
-  // Load and add window or tab data for a foreign session to our internal
+  // Load and add window or tab data from synced specifics to our internal
   // tracking.
-  void UpdateTrackerWithForeignSession(
-      const sync_pb::SessionSpecifics& specifics,
-      const base::Time& modification_time);
+  void UpdateTrackerWithSpecifics(const sync_pb::SessionSpecifics& specifics,
+                                  const base::Time& modification_time);
 
   // Returns true if |sync_data| contained a header node for the current
-  // machine, false otherwise. |restored_tabs| is a filtered tab-only
-  // subset of |sync_data| returned by this function for convenience.
-  // |new_changes| is a link to the SyncChange pipeline that exists in the
-  // caller's context. This function will append necessary changes for
-  // processing later.
+  // machine, false otherwise. |new_changes| is a link to the SyncChange
+  // pipeline that exists in the caller's context. This function will append
+  // necessary changes for processing later.
   bool InitFromSyncModel(const syncer::SyncDataList& sync_data,
-                         syncer::SyncDataList* restored_tabs,
                          syncer::SyncChangeList* new_changes);
 
   // Helper to construct a deletion SyncChange for a *tab node*.
   // Caller should check IsValid() on the returned change, as it's possible
   // this node could not be deleted.
   syncer::SyncChange TombstoneTab(const sync_pb::SessionSpecifics& tab);
 
   // Helper method to load the favicon data from the tab specifics. If the
   // favicon is valid, stores the favicon data into the favicon cache.
   void RefreshFaviconVisitTimesFromForeignTab(
@@ skipping 28 matching lines @@
                                        sessions::SessionWindow* session_window);
 
   // Resync local window information. Updates the local sessions header node
   // with the status of open windows and the order of tabs they contain. Should
   // only be called for changes that affect a window, not a change within a
   // single tab.
   //
   // RELOAD_TABS will additionally cause a resync of all tabs (same as calling
   // AssociateTabs with a vector of all tabs).
   //
-  // |restored_tabs| is a filtered tab-only subset of initial sync data, if
-  // available (during MergeDataAndStartSyncing). It can be used to obtain
-  // baseline SessionSpecifics for tabs we can't fully associate any other
-  // way because they don't yet have a WebContents.
-  //
   // Returns: false if the local session's sync nodes were deleted and
   // reassociation is necessary, true otherwise.
   //
   // |change_output| *must* be provided as a link to the SyncChange pipeline
   // that exists in the caller's context. This function will append necessary
   // changes for processing later.
   enum ReloadTabsOption { RELOAD_TABS, DONT_RELOAD_TABS };
   void AssociateWindows(ReloadTabsOption option,
-                        const syncer::SyncDataList& restored_tabs,
                         syncer::SyncChangeList* change_output);
 
   // Loads and reassociates the local tabs referenced in |tabs|.
   // |change_output| *must* be provided as a link to the SyncChange pipeline
   // that exists in the caller's context. This function will append necessary
   // changes for processing later.
   void AssociateTab(SyncedTabDelegate* const tab,
                     syncer::SyncChangeList* change_output);
 
   // Set |session_tab| from |tab_delegate| and |mtime|.
   void SetSessionTabFromDelegate(const SyncedTabDelegate& tab_delegate,
                                  base::Time mtime,
                                  sessions::SessionTab* session_tab);
 
   // Sets |variation_ids| field of |session_tab| with the ids of the currently
   // assigned variations which should be sent to sync.
   static void SetVariationIds(sessions::SessionTab* session_tab);
 
   // Populates |specifics| based on the data in |tab_delegate|.
   void LocalTabDelegateToSpecifics(const SyncedTabDelegate& tab_delegate,
                                    sync_pb::SessionSpecifics* specifics);
 
   // It's possible that when we associate windows, tabs aren't all loaded
   // into memory yet (e.g on android) and we don't have a WebContents. In this
   // case we can't do a full association, but we still want to update tab IDs
   // as they may have changed after a session was restored.  This method
   // compares new_tab_id and new_window_id against the previously persisted tab
   // ID and window ID (from our TabNodePool) and updates them if either differs.
-  // |restored_tabs| is a filtered tab-only subset of initial sync data, if
-  // available (during MergeDataAndStartSyncing). It can be used to obtain
-  // baseline SessionSpecifics for tabs we can't fully associate any other
-  // way because they don't yet have a WebContents.
-  // TODO(tim): Bug 98892. We should be able to test this for this on android
-  // even though we didn't have tests for old API-based sessions sync.
   void AssociateRestoredPlaceholderTab(
       const SyncedTabDelegate& tab_delegate,
       SessionID::id_type new_tab_id,
       SessionID::id_type new_window_id,
-      const syncer::SyncDataList& restored_tabs,
       syncer::SyncChangeList* change_output);
 
   // Stops and re-starts syncing to rebuild association mappings. Returns true
   // when re-starting succeeds.
   // See |local_tab_pool_out_of_sync_|.
   bool RebuildAssociations();
 
   // Validates the content of a SessionHeader protobuf.
   // Returns false if validation fails.
   static bool IsValidSessionHeader(const sync_pb::SessionHeader& header);
 
   // Calculates the tag hash from a specifics object. Calculating the hash is
   // something we typically want to avoid doing in the model type like this.
   // However, the only place that understands how to generate a tag from the
   // specifics is the model type, ie us. We need to generate the tag because it
   // is not passed over the wire for remote data. The use case this function was
   // created for is detecting bad tag hashes from remote data, see
   // crbug.com/604657.
   static std::string TagHashFromSpecifics(
       const sync_pb::SessionSpecifics& specifics);
 
   SyncedWindowDelegatesGetter* synced_window_delegates_getter() const;
 
   // The client of this sync sessions datatype.
   SyncSessionsClient* const sessions_client_;
 
-  // Mapping of current open (local) tabs to their sync identifiers.
-  TabLinksMap local_tab_map_;
-
   SyncedSessionTracker session_tracker_;
   FaviconCache favicon_cache_;
 
-  // Pool of used/available sync nodes associated with local tabs.
-  TabNodePool local_tab_pool_;
-
   // Tracks whether our local representation of which sync nodes map to what
   // tabs (belonging to the current local session) is inconsistent.  This can
   // happen if a foreign client deems our session as "stale" and decides to
   // delete it. Rather than respond by bullishly re-creating our nodes
   // immediately, which could lead to ping-pong sequences, we give the benefit
   // of the doubt and hold off until another local navigation occurs, which
   // proves that we are still relevant.
   bool local_tab_pool_out_of_sync_;
 
   syncer::SyncPrefs* sync_prefs_;
@@ skipping 32 matching lines @@
 
   // Callback to inform sync that a sync data refresh is requested.
   base::Closure datatype_refresh_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionsSyncManager);
 };
 
 }  // namespace sync_sessions
 
 #endif  // COMPONENTS_SYNC_SESSIONS_SESSIONS_SYNC_MANAGER_H_