In the TabRestoreService, do not create Window entries that only have 1 Tab.

BUG=56744
TEST=Open a window and navigate 1 tab. Close window. Both NTP and the Mac History menu show the tab, without being in a window.

Review URL: http://codereview.chromium.org/3397032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@62537 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 42 insertions, 12 deletions

diff --git a/chrome/browser/sessions/session_restore_browsertest.cc b/chrome/browser/sessions/session_restore_browsertest.cc
index 8ec1281..9ff065d 100644
--- a/chrome/browser/sessions/session_restore_browsertest.cc
+++ b/chrome/browser/sessions/session_restore_browsertest.cc
@@ -117,3 +117,31 @@ IN_PROC_BROWSER_TEST_F(SessionRestoreTest, RestoreIndividualTabFromWindow) {
   window = static_cast<TabRestoreService::Window*>(service->entries().front());
   EXPECT_EQ(2U, window->tabs.size());
 }
+
+IN_PROC_BROWSER_TEST_F(SessionRestoreTest, WindowWithOneTab) {
+  GURL url(ui_test_utils::GetTestUrl(
+      FilePath(FilePath::kCurrentDirectory),
+      FilePath(FILE_PATH_LITERAL("title1.html"))));
+
+  // Add a single tab.
+  ui_test_utils::NavigateToURL(browser(), url);
+
+  TabRestoreService* service = browser()->profile()->GetTabRestoreService();
+  service->ClearEntries();
+  EXPECT_EQ(0U, service->entries().size());
+
+  // Close the window.
+  browser()->window()->Close();
+
+  // Expect the window to be converted to a tab by the TRS.
+  EXPECT_EQ(1U, service->entries().size());
+  ASSERT_EQ(TabRestoreService::TAB, service->entries().front()->type);
+  const TabRestoreService::Tab* tab =
+      static_cast<TabRestoreService::Tab*>(service->entries().front());
+
+  // Restore the tab.
+  service->RestoreEntryById(NULL, tab->id, false);
+
+  // Make sure the restore was successful.
+  EXPECT_EQ(0U, service->entries().size());
+}
diff --git a/chrome/browser/sessions/tab_restore_service.cc b/chrome/browser/sessions/tab_restore_service.cc
index 5b5f59f..3d78771 100644
--- a/chrome/browser/sessions/tab_restore_service.cc
+++ b/chrome/browser/sessions/tab_restore_service.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -222,7 +222,7 @@ void TabRestoreService::BrowserClosing(Browser* browser) {
 
   closing_browsers_.insert(browser);
 
-  Window* window = new Window();
+  scoped_ptr<Window> window(new Window());
   window->selected_tab_index = browser->selected_index();
   window->timestamp = TimeNow();
   // Don't use std::vector::resize() because it will push copies of an empty tab
@@ -242,14 +242,16 @@ void TabRestoreService::BrowserClosing(Browser* browser) {
       entry_index++;
     }
   }
-  if (window->tabs.empty()) {
-    delete window;
-    window = NULL;
-  } else {
+  if (window->tabs.size() == 1) {
+    // Short-circuit creating a Window if only 1 tab was present. This fixes
+    // http://crbug.com/56744. Copy the Tab because it's owned by an object on
+    // the stack.
+    AddEntry(new Tab(window->tabs[0]), true, true);
+  } else if (!window->tabs.empty()) {
     window->selected_tab_index =
         std::min(static_cast<int>(window->tabs.size() - 1),
                  window->selected_tab_index);
-    AddEntry(window, true, true);
+    AddEntry(window.release(), true, true);
   }
 }
 
diff --git a/chrome/browser/sessions/tab_restore_service.h b/chrome/browser/sessions/tab_restore_service.h
index 48c9dab..932de55 100644
--- a/chrome/browser/sessions/tab_restore_service.h
+++ b/chrome/browser/sessions/tab_restore_service.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -202,10 +202,10 @@ class TabRestoreService : public BaseSessionService {
   // Notifies observers the tabs have changed.
   void NotifyTabsChanged();
 
-  // Adds |entry| to the list of entries. If |prune| is true |PruneAndNotify|
-  // is invoked. If |to_front| is true the entry is added to the front,
-  // otherwise the back. Normal closes go to the front, but tab/window closes
-  // from the previous session are added to the back.
+  // Adds |entry| to the list of entries and takes ownership. If |prune| is true
+  // |PruneAndNotify| is invoked. If |to_front| is true the entry is added to
+  // the front, otherwise the back. Normal closes go to the front, but
+  // tab/window closes from the previous session are added to the back.
   void AddEntry(Entry* entry, bool prune, bool to_front);
 
   // Prunes entries_ to contain only kMaxEntries and invokes NotifyTabsChanged.