[ios] Allow having multiple session windows in a session.

ios/chrome/browser/tabs/tab_model.mm

 // Copyright 2012 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.
 
 #import "ios/chrome/browser/tabs/tab_model.h"
 
 #include <cstdint>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #import "base/mac/foundation_util.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics_action.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "components/sessions/core/serialized_navigation_entry.h"
 #include "components/sessions/core/session_id.h"
 #include "components/sessions/core/tab_restore_service.h"
 #include "components/sessions/ios/ios_live_tab.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/chrome_url_constants.h"
 #import "ios/chrome/browser/chrome_url_util.h"
 #import "ios/chrome/browser/metrics/tab_usage_recorder.h"
 #import "ios/chrome/browser/metrics/tab_usage_recorder_web_state_list_observer.h"
 #include "ios/chrome/browser/sessions/ios_chrome_tab_restore_service_factory.h"
+#import "ios/chrome/browser/sessions/session_ios.h"
 #import "ios/chrome/browser/sessions/session_service_ios.h"
 #import "ios/chrome/browser/sessions/session_window_ios.h"
 #import "ios/chrome/browser/snapshots/snapshot_cache.h"
 #import "ios/chrome/browser/snapshots/snapshot_cache_web_state_list_observer.h"
 #include "ios/chrome/browser/tab_parenting_global_observer.h"
 #import "ios/chrome/browser/tabs/legacy_tab_helper.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/tabs/tab_model_closing_web_state_observer.h"
 #import "ios/chrome/browser/tabs/tab_model_list.h"
 #import "ios/chrome/browser/tabs/tab_model_observers.h"
@@ skipping 124 matching lines @@
   // Saves session's state.
   base::scoped_nsobject<SessionServiceIOS> _sessionService;
   // List of TabModelObservers.
   base::scoped_nsobject<TabModelObservers> _observers;
 
   // Used to ensure thread-safety of the certificate policy management code.
   base::CancelableTaskTracker _clearPoliciesTaskTracker;
 }
 
 // Session window for the contents of the tab model.
-@property(nonatomic, readonly) SessionWindowIOS* windowForSavingSession;
+@property(nonatomic, readonly) SessionIOS* sessionForSaving;
 
 // Helper method that posts a notification with the given name with |tab|
 // in the userInfo dictionary under the kTabModelTabKey.
 - (void)postNotificationName:(NSString*)notificationName withTab:(Tab*)tab;
 
 // Helper method to restore a saved session and control if the state should
 // be persisted or not. Used to implement the public -restoreSessionWindow:
 // method and restoring session in the initialiser.
 - (BOOL)restoreSessionWindow:(SessionWindowIOS*)window
                 persistState:(BOOL)persistState;
@@ skipping 20 matching lines @@
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 
   // Clear weak pointer to WebStateListMetricsObserver before destroying it.
   _webStateListMetricsObserver = nullptr;
 
   // Close all tabs. Do this in an @autoreleasepool as WebStateList observers
   // will be notified (they are unregistered later). As some of them may be
   // implemented in Objective-C and unregister themselves in their -dealloc
   // method, ensure they -autorelease introduced by ARC are processed before
   // the WebStateList destructor is called.
   @autoreleasepool {

[marq (ping after 24h), 2017/04/18 15:16:55]

This file isn't ARC yet. Should this be a ScopedAutoreleasePool?

[sdefresne, 2017/04/19 14:54:41]

@autoreleasepool is not related to ARC and can be used for file compiled without
ARC. From clang documentation:

  @autoreleasepool may be used in non-ARC translation units,
  with equivalent semantics.

http://clang.llvm.org/docs/AutomaticReferenceCounting.html#autoreleasepool

     [self closeAllTabs];
   }
 
   // Unregister all observers after closing all the tabs as some of them are
   // required to properly clean up the Tabs.
   for (const auto& webStateListObserver : _webStateListObservers)
     _webStateList->RemoveObserver(webStateListObserver.get());
   _webStateListObservers.clear();
   _retainedWebStateListObservers.reset();
 
@@ skipping 161 matching lines @@
   return [self restoreSessionWindow:window persistState:YES];
 }
 
 - (void)saveSessionImmediately:(BOOL)immediately {
   // Do nothing if there are tabs in the model but no selected tab. This is
   // a transitional state.
   if ((!self.currentTab && _webStateList->count()) || !_browserState)
     return;
   NSString* statePath =
       base::SysUTF8ToNSString(_browserState->GetStatePath().AsUTF8Unsafe());
-  [_sessionService saveSessionWindow:self.windowForSavingSession
-                           directory:statePath
-                         immediately:immediately];
+  [_sessionService saveSession:self.sessionForSaving
+                     directory:statePath
+                   immediately:immediately];
 }
 
 - (Tab*)tabAtIndex:(NSUInteger)index {
   DCHECK_LE(index, static_cast<NSUInteger>(INT_MAX));
   return LegacyTabHelper::GetTabForWebState(
       _webStateList->GetWebStateAt(static_cast<int>(index)));
 }
 
 - (NSUInteger)indexOfTab:(Tab*)tab {
   int index = _webStateList->GetIndexOfWebState(tab.webState);
@@ skipping 274 matching lines @@
   NSUInteger count = 0;
   for (Tab* tab in self) {
     if ([tab.webController isViewAlive])
       count++;
   }
   return count;
 }
 
 #pragma mark - Private methods
 
-- (SessionWindowIOS*)windowForSavingSession {
+- (SessionIOS*)sessionForSaving {
   // Background tabs will already have their state preserved, but not the
   // fg tab. Do it now.
   [self.currentTab recordStateInHistory];
 
   // Build the array of sessions. Copy the session objects as the saving will
   // be done on a separate thread.
   // TODO(crbug.com/661986): This could get expensive especially since this
   // window may never be saved (if another call comes in before the delay).
-  return [[[SessionWindowIOS alloc]
+  SessionWindowIOS* sessionWindow = [[[SessionWindowIOS alloc]
       initWithSessions:SerializeWebStateList(_webStateList.get())
          selectedIndex:[self indexOfTab:self.currentTab]] autorelease];
+  return [[SessionIOS alloc] initWithWindows:@[ sessionWindow ]];
 }
 
 - (void)postNotificationName:(NSString*)notificationName withTab:(Tab*)tab {
   // A scoped_nsobject is used rather than an NSDictionary with static
   // initializer dictionaryWithObject, because that approach adds the dictionary
   // to the autorelease pool, which in turn holds Tab alive longer than
   // necessary.
   base::scoped_nsobject<NSDictionary> userInfo(
       [[NSDictionary alloc] initWithObjectsAndKeys:tab, kTabModelTabKey, nil]);
   [[NSNotificationCenter defaultCenter] postNotificationName:notificationName
@@ skipping 106 matching lines @@
 }
 
 // Called when UIApplicationWillEnterForegroundNotification is received.
 - (void)applicationWillEnterForeground:(NSNotification*)notify {
   if (_tabUsageRecorder) {
     _tabUsageRecorder->AppWillEnterForeground();
   }
 }
 
 @end