Makes the tab restore service contain any windows that were open at

the time of a crash.

BUG=5465
TEST=Bring up chrome, go to google.com. Wait a minute. Kill chrome via
  the task manager. Launch chrome again. Make sure the new tab page
  shows an entry named 'Window (g)' where g is Google's favicon.

Review URL: http://codereview.chromium.org/14172

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7188 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 330 insertions, 30 deletions

diff --git a/chrome/browser/sessions/session_restore.cc b/chrome/browser/sessions/session_restore.cc
index e9e0b1d1..8ffbac9 100644
--- a/chrome/browser/sessions/session_restore.cc
+++ b/chrome/browser/sessions/session_restore.cc
@@ -424,6 +424,7 @@ static void Restore(Profile* profile,
     NOTREACHED();
     return;
   }
+  profile->set_restored_last_session(true);
   // SessionRestoreImpl takes care of deleting itself when done.
   SessionRestoreImpl* restorer =
       new SessionRestoreImpl(profile, browser, synchronous,
diff --git a/chrome/browser/sessions/tab_restore_service.cc b/chrome/browser/sessions/tab_restore_service.cc
index f12e6d9..13da68f 100644
--- a/chrome/browser/sessions/tab_restore_service.cc
+++ b/chrome/browser/sessions/tab_restore_service.cc
@@ -12,6 +12,7 @@
 #include "chrome/browser/navigation_entry.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/sessions/session_backend.h"
+#include "chrome/browser/sessions/session_service.h"
 #include "chrome/common/scoped_vector.h"
 #include "chrome/common/stl_util-inl.h"
 
@@ -28,8 +29,8 @@ TabRestoreService::Entry::Entry(Type type) : id(next_entry_id++), type(type) {}
 
 // TabRestoreService ----------------------------------------------------------
 
-// Max number of entries we'll keep around.
-static const size_t kMaxEntries = 10;
+// static
+const size_t TabRestoreService::kMaxEntries = 10;
 
 // Identifier for commands written to file.
 // The ordering in the file is as follows:
@@ -64,7 +65,7 @@ struct WindowPayload {
   int32 num_tabs;
 };
 
-// Paylowed used for the start of a tab close.
+// Payload used for the start of a tab close.
 struct SelectedNavigationInTabPayload {
   SessionID::id_type id;
   int32 index;
@@ -92,7 +93,7 @@ void RemoveEntryByID(SessionID::id_type id,
 TabRestoreService::TabRestoreService(Profile* profile)
     : BaseSessionService(BaseSessionService::TAB_RESTORE, profile,
                          std::wstring()),
-      loaded_last_session_(false),
+      load_state_(NOT_LOADED),
       restoring_(false),
       reached_max_(false),
       entries_to_write_(0),
@@ -105,6 +106,7 @@ TabRestoreService::~TabRestoreService() {
 
   FOR_EACH_OBSERVER(Observer, observer_list_, TabRestoreServiceDestroyed(this));
   STLDeleteElements(&entries_);
+  STLDeleteElements(&staging_entries_);
 }
 
 void TabRestoreService::AddObserver(Observer* observer) {
@@ -242,15 +244,30 @@ void TabRestoreService::RestoreEntryById(Browser* browser,
 }
 
 void TabRestoreService::LoadTabsFromLastSession() {
-  if (loaded_last_session_ || reached_max_)
+  if (load_state_ != NOT_LOADED || reached_max_)
     return;
 
-  loaded_last_session_ = true;
+  load_state_ = LOADING;
 
+  if (!profile()->restored_last_session() &&
+      !profile()->DidLastSessionExitCleanly() &&
+      profile()->GetSessionService()) {
+    // The previous session crashed and wasn't restored. Load the tabs/windows
+    // that were open at the point of crash from the session service.
+    profile()->GetSessionService()->GetLastSession(
+        &load_consumer_,
+        NewCallback(this, &TabRestoreService::OnGotPreviousSession));
+  } else {
+    load_state_ |= LOADED_LAST_SESSION;
+  }
+
+  // Request the tabs closed in the last session. If the last session crashed,
+  // this won't contain the tabs/window that were open at the point of the
+  // crash (the call to GetLastSession above requests those).
   ScheduleGetLastSessionCommands(
       new InternalGetCommandsRequest(
           NewCallback(this, &TabRestoreService::OnGotLastSessionCommands)),
-      &load_tabs_consumer_);
+      &load_consumer_);
 }
 
 void TabRestoreService::Save() {
@@ -466,6 +483,18 @@ int TabRestoreService::GetSelectedNavigationIndexToPersist(const Tab& tab) {
 void TabRestoreService::OnGotLastSessionCommands(
     Handle handle,
     scoped_refptr<InternalGetCommandsRequest> request) {
+  std::vector<Entry*> entries;
+  CreateEntriesFromCommands(request, &entries);
+  // Closed tabs always go to the end.
+  staging_entries_.insert(staging_entries_.end(), entries.begin(),
+                          entries.end());
+  load_state_ |= LOADED_LAST_TABS;
+  LoadStateChanged();
+}
+
+void TabRestoreService::CreateEntriesFromCommands(
+    scoped_refptr<InternalGetCommandsRequest> request,
+    std::vector<Entry*>* loaded_entries) {
   if (request->canceled() || entries_.size() == kMaxEntries)
     return;
 
@@ -575,23 +604,7 @@ void TabRestoreService::OnGotLastSessionCommands(
   // entries with no navigations.
   ValidateAndDeleteEmptyEntries(&(entries.get()));
 
-  if (entries->empty())
-    return;
-
-  // And add them.
-  for (size_t i = 0; i < entries->size(); ++i)
-    AddEntry(entries[i], false, false);
-
-  // AddEntry takes ownership of the entry, need to clear out entries so that
-  // it doesn't delete them.
-  entries->clear();
-
-  // Make it so we rewrite all the tabs. We need to do this otherwise we won't
-  // correctly write out the entries when Save is invoked (Save starts from
-  // the front, not the end and we just added the entries to the end).
-  entries_to_write_ = entries_.size();
-
-  PruneAndNotify();
+  loaded_entries->swap(entries.get());
 }
 
 bool TabRestoreService::ValidateTab(Tab* tab) {
@@ -647,3 +660,90 @@ void TabRestoreService::ValidateAndDeleteEmptyEntries(
   // Delete the remaining entries.
   STLDeleteElements(&invalid_entries);
 }
+
+void TabRestoreService::OnGotPreviousSession(
+    Handle handle,
+    std::vector<SessionWindow*>* windows) {
+  std::vector<Entry*> entries;
+  CreateEntriesFromWindows(windows, &entries);
+  // Previous session tabs go first.
+  staging_entries_.insert(staging_entries_.begin(), entries.begin(),
+                          entries.end());
+  load_state_ |= LOADED_LAST_SESSION;
+  LoadStateChanged();
+}
+
+void TabRestoreService::CreateEntriesFromWindows(
+    std::vector<SessionWindow*>* windows,
+    std::vector<Entry*>* entries) {
+  for (size_t i = 0; i < windows->size(); ++i) {
+    scoped_ptr<Window> window(new Window());
+    if (ConvertSessionWindowToWindow((*windows)[i], window.get()))
+      entries->push_back(window.release());
+  }
+}
+
+bool TabRestoreService::ConvertSessionWindowToWindow(
+    SessionWindow* session_window,
+    Window* window) {
+  for (size_t i = 0; i < session_window->tabs.size(); ++i) {
+    if (!session_window->tabs[i]->navigations.empty()) {
+      window->tabs.resize(window->tabs.size() + 1);
+      Tab& tab = window->tabs.back();
+      tab.navigations.swap(session_window->tabs[i]->navigations);
+      tab.current_navigation_index =
+          session_window->tabs[i]->current_navigation_index;
+    }
+  }
+  if (window->tabs.empty())
+    return false;
+
+  window->selected_tab_index =
+      std::min(session_window->selected_tab_index,
+               static_cast<int>(window->tabs.size() - 1));
+  return true;
+}
+
+void TabRestoreService::LoadStateChanged() {
+  if ((load_state_ & (LOADED_LAST_TABS | LOADED_LAST_SESSION)) !=
+      (LOADED_LAST_TABS | LOADED_LAST_SESSION)) {
+    // Still waiting on previous session or previous tabs.
+    return;
+  }
+
+  // We're done loading.
+  load_state_ ^= LOADING;
+
+  if (staging_entries_.empty() || reached_max_) {
+    STLDeleteElements(&staging_entries_);
+    return;
+  }
+
+  if (staging_entries_.size() + entries_.size() > kMaxEntries) {
+    // If we add all the staged entries we'll end up with more than
+    // kMaxEntries. Delete entries such that we only end up with
+    // at most kMaxEntries.
+    DCHECK(entries_.size() < kMaxEntries);
+    STLDeleteContainerPointers(
+        staging_entries_.begin() + (kMaxEntries - entries_.size()),
+        staging_entries_.end());
+    staging_entries_.erase(
+        staging_entries_.begin() + (kMaxEntries - entries_.size()),
+        staging_entries_.end());
+  }
+
+  // And add them.
+  for (size_t i = 0; i < staging_entries_.size(); ++i)
+    AddEntry(staging_entries_[i], false, false);
+
+  // AddEntry takes ownership of the entry, need to clear out entries so that
+  // it doesn't delete them.
+  staging_entries_.clear();
+
+  // Make it so we rewrite all the tabs. We need to do this otherwise we won't
+  // correctly write out the entries when Save is invoked (Save starts from
+  // the front, not the end and we just added the entries to the end).
+  entries_to_write_ = staging_entries_.size();
+
+  PruneAndNotify();
+}
diff --git a/chrome/browser/sessions/tab_restore_service.h b/chrome/browser/sessions/tab_restore_service.h
index adf5df5..2962cf5 100644
--- a/chrome/browser/sessions/tab_restore_service.h
+++ b/chrome/browser/sessions/tab_restore_service.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_H_
 
 #include <list>
+#include <vector>
 
 #include "base/observer_list.h"
 #include "base/time.h"
@@ -126,14 +127,35 @@ class TabRestoreService : public BaseSessionService {
                         SessionID::id_type id,
                         bool replace_existing_tab);
 
-  // Loads the tabs from the previous session. This does nothing if the tabs
+  // Loads the tabs and previous session. This does nothing if the tabs
   // from the previous session have already been loaded.
   void LoadTabsFromLastSession();
 
+  // Max number of entries we'll keep around.
+  static const size_t kMaxEntries;
+
  protected:
   virtual void Save();
 
  private:
+  // Used to indicate what has loaded.
+  enum LoadState {
+    // Indicates we haven't loaded anything.
+    NOT_LOADED           = 1 << 0,
+
+    // Indicates we've asked for the last sessions and tabs but haven't gotten
+    // the result back yet.
+    LOADING              = 1 << 2,
+
+    // Indicates we finished loading the last tabs (but not necessarily the
+    // last session).
+    LOADED_LAST_TABS     = 1 << 3,
+
+    // Indicates we finished loading the last session (but not necessarily the
+    // last tabs).
+    LOADED_LAST_SESSION  = 1 << 4
+  };
+
   // Populates tabs->navigations from the NavigationController.
   void PopulateTabFromController(NavigationController* controller,
                                  Tab* tab);
@@ -179,12 +201,18 @@ class TabRestoreService : public BaseSessionService {
   // no valid navigation to persist.
   int GetSelectedNavigationIndexToPersist(const Tab& tab);
 
-  // Invoked when we've loaded the session commands from the previous run.
-  // This creates entries and adds them to entries_, notifying the observer.
+  // Invoked when we've loaded the session commands that identify the
+  // previously closed tabs. This creates entries, adds them to
+  // staging_entries_, and invokes LoadState.
   void OnGotLastSessionCommands(
       Handle handle,
       scoped_refptr<InternalGetCommandsRequest> request);
 
+  // Populates |loaded_entries| with Entries from |request|.
+  void CreateEntriesFromCommands(
+      scoped_refptr<InternalGetCommandsRequest> request,
+      std::vector<Entry*>* loaded_entries);
+
   // Returns true if |tab| has more than one navigation. If |tab| has more
   // than one navigation |tab->current_navigation_index| is constrained based
   // on the number of navigations.
@@ -195,11 +223,32 @@ class TabRestoreService : public BaseSessionService {
   // hold.
   void ValidateAndDeleteEmptyEntries(std::vector<Entry*>* entries);
 
+  // Callback from SessionService when we've received the windows from the
+  // previous session. This creates and add entries to |staging_entries_|
+  // and invokes LoadStateChanged.
+  void OnGotPreviousSession(Handle handle,
+                            std::vector<SessionWindow*>* windows);
+
+  // Creates and add entries to |entries| for each of the windows in |windows|.
+  void CreateEntriesFromWindows(
+      std::vector<SessionWindow*>* windows,
+      std::vector<Entry*>* entries);
+
+  // Converts a SessionWindow into a Window, returning true on success.
+  bool ConvertSessionWindowToWindow(
+      SessionWindow* session_window,
+      Window* window);
+
+  // Invoked when previous tabs or session is loaded. If both have finished
+  // loading the entries in staging_entries_ are added to entries_ and
+  // observers are notified.
+  void LoadStateChanged();
+
   // Set of entries.
   Entries entries_;
 
   // Whether we've loaded the last session.
-  bool loaded_last_session_;
+  int load_state_;
 
   // Are we restoring a tab? If this is true we ignore requests to create a
   // historical tab.
@@ -221,8 +270,14 @@ class TabRestoreService : public BaseSessionService {
   // avoid creating historical tabs for them.
   std::set<Browser*> closing_browsers_;
 
-  // Used when loading commands from the previous session.
-  CancelableRequestConsumer load_tabs_consumer_;
+  // Used when loading previous tabs/session.
+  CancelableRequestConsumer load_consumer_;
+
+  // Results from previously closed tabs/sessions is first added here. When
+  // the results from both us and the session restore service have finished
+  // loading LoadStateChanged is invoked, which adds these entries to
+  // entries_.
+  std::vector<Entry*> staging_entries_;
 
   DISALLOW_COPY_AND_ASSIGN(TabRestoreService);
 };
diff --git a/chrome/browser/sessions/tab_restore_service_unittest.cc b/chrome/browser/sessions/tab_restore_service_unittest.cc
index 99e65c3..2f7d4ba 100644
--- a/chrome/browser/sessions/tab_restore_service_unittest.cc
+++ b/chrome/browser/sessions/tab_restore_service_unittest.cc
@@ -53,6 +53,34 @@ class TabRestoreServiceTest : public testing::Test {
     service_->LoadTabsFromLastSession();
   }
 
+  // Adds a window with one tab and url to the profile's session service.
+  void AddWindowWithOneTabToSessionService() {
+    SessionService* session_service = profile_->GetSessionService();
+    SessionID tab_id;
+    SessionID window_id;
+    session_service->SetWindowType(window_id, Browser::TYPE_NORMAL);
+    session_service->SetTabWindow(window_id, tab_id);
+    session_service->SetTabIndexInWindow(window_id, tab_id, 0);
+    session_service->SetSelectedTabInWindow(window_id, 0);
+    NavigationEntry entry(tab_contents_factory_->type());
+    entry.set_url(url1_);
+    session_service->UpdateTabNavigation(window_id, tab_id, 0, entry);
+  }
+
+  // Creates a SessionService and assigns it to the Profile. The SessionService
+  // is configured with a single window with a single tab pointing at url1_ by
+  // way of AddWindowWithOneTabToSessionService.
+  void CreateSessionServiceWithOneWindow() {
+    // The profile takes ownership of this.
+    SessionService* session_service = new SessionService(profile_.get());
+    profile_->set_session_service(session_service);
+
+    AddWindowWithOneTabToSessionService();
+
+    // Set this, otherwise previous session won't be loaded.
+    profile_->set_last_session_exited_cleanly(false);
+  }
+
   GURL url1_;
   GURL url2_;
   GURL url3_;
@@ -244,3 +272,119 @@ TEST_F(TabRestoreServiceTest, DontLoadTwice) {
   // There should only be one entry.
   ASSERT_EQ(1, service_->entries().size());
 }
+
+// Makes sure we load the previous session as necessary.
+TEST_F(TabRestoreServiceTest, LoadPreviousSession) {
+  CreateSessionServiceWithOneWindow();
+
+  profile_->GetSessionService()->MoveCurrentSessionToLastSession();
+
+  service_->LoadTabsFromLastSession();
+
+  // Make sure we get back one entry with one tab whose url is url1.
+  ASSERT_EQ(1, service_->entries().size());
+  TabRestoreService::Entry* entry2 = service_->entries().front();
+  ASSERT_EQ(TabRestoreService::WINDOW, entry2->type);
+  TabRestoreService::Window* window =
+      static_cast<TabRestoreService::Window*>(entry2);
+  ASSERT_EQ(1, window->tabs.size());
+  EXPECT_EQ(0, window->selected_tab_index);
+  ASSERT_EQ(1, window->tabs[0].navigations.size());
+  EXPECT_EQ(0, window->tabs[0].current_navigation_index);
+  EXPECT_TRUE(url1_ == window->tabs[0].navigations[0].url());
+}
+
+// Makes sure we don't attempt to load previous sessions after a restore.
+TEST_F(TabRestoreServiceTest, DontLoadAfterRestore) {
+  CreateSessionServiceWithOneWindow();
+
+  profile_->GetSessionService()->MoveCurrentSessionToLastSession();
+
+  profile_->set_restored_last_session(true);
+
+  service_->LoadTabsFromLastSession();
+
+  // Because we restored a session TabRestoreService shouldn't load the tabs.
+  ASSERT_EQ(0, service_->entries().size());
+}
+
+// Makes sure we don't attempt to load previous sessions after a clean exit.
+TEST_F(TabRestoreServiceTest, DontLoadAfterCleanExit) {
+  CreateSessionServiceWithOneWindow();
+
+  profile_->GetSessionService()->MoveCurrentSessionToLastSession();
+
+  profile_->set_last_session_exited_cleanly(true);
+
+  service_->LoadTabsFromLastSession();
+
+  ASSERT_EQ(0, service_->entries().size());
+}
+
+TEST_F(TabRestoreServiceTest, LoadPreviousSessionAndTabs) {
+  CreateSessionServiceWithOneWindow();
+
+  profile_->GetSessionService()->MoveCurrentSessionToLastSession();
+
+  AddThreeNavigations();
+
+  service_->CreateHistoricalTab(controller_);
+
+  RecreateService();
+
+  // We should get back two entries, one from the previous session and one from
+  // the tab restore service. The previous session entry should be first.
+  ASSERT_EQ(2, service_->entries().size());
+  // The first entry should come from the session service.
+  TabRestoreService::Entry* entry = service_->entries().front();
+  ASSERT_EQ(TabRestoreService::WINDOW, entry->type);
+  TabRestoreService::Window* window =
+      static_cast<TabRestoreService::Window*>(entry);
+  ASSERT_EQ(1, window->tabs.size());
+  EXPECT_EQ(0, window->selected_tab_index);
+  ASSERT_EQ(1, window->tabs[0].navigations.size());
+  EXPECT_EQ(0, window->tabs[0].current_navigation_index);
+  EXPECT_TRUE(url1_ == window->tabs[0].navigations[0].url());
+
+  // Then the closed tab.
+  entry = *(++service_->entries().begin());
+  ASSERT_EQ(TabRestoreService::TAB, entry->type);
+  TabRestoreService::Tab* tab = static_cast<TabRestoreService::Tab*>(entry);
+  ASSERT_EQ(3, tab->navigations.size());
+  EXPECT_EQ(2, tab->current_navigation_index);
+  EXPECT_TRUE(url1_ == tab->navigations[0].url());
+  EXPECT_TRUE(url2_ == tab->navigations[1].url());
+  EXPECT_TRUE(url3_ == tab->navigations[2].url());
+}
+
+// Creates TabRestoreService::kMaxEntries + 1 windows in the session service
+// and makes sure we only get back TabRestoreService::kMaxEntries on restore.
+TEST_F(TabRestoreServiceTest, ManyWindowsInSessionService) {
+  CreateSessionServiceWithOneWindow();
+
+  for (size_t i = 0; i < TabRestoreService::kMaxEntries; ++i)
+    AddWindowWithOneTabToSessionService();
+
+  profile_->GetSessionService()->MoveCurrentSessionToLastSession();
+
+  AddThreeNavigations();
+
+  service_->CreateHistoricalTab(controller_);
+
+  RecreateService();
+
+  // We should get back kMaxEntries entries. We added more, but
+  // TabRestoreService only allows up to kMaxEntries.
+  ASSERT_EQ(TabRestoreService::kMaxEntries, service_->entries().size());
+
+  // The first entry should come from the session service.
+  TabRestoreService::Entry* entry = service_->entries().front();
+  ASSERT_EQ(TabRestoreService::WINDOW, entry->type);
+  TabRestoreService::Window* window =
+      static_cast<TabRestoreService::Window*>(entry);
+  ASSERT_EQ(1, window->tabs.size());
+  EXPECT_EQ(0, window->selected_tab_index);
+  ASSERT_EQ(1, window->tabs[0].navigations.size());
+  EXPECT_EQ(0, window->tabs[0].current_navigation_index);
+  EXPECT_TRUE(url1_ == window->tabs[0].navigations[0].url());
+}