Ensure History > Recent Tabs restore preserves window disposition.

chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc

Index: chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
diff --git a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
index aaac0456e74576a42635edea8511d39e49862da9..938632c65fdf3c28c037b1f92f31f059374e257c 100644
--- a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
+++ b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
@@ -464,11 +464,22 @@ void RecentTabsSubMenuModel::BuildLocalEntries() {
           break;
         }
         case sessions::TabRestoreService::WINDOW: {
-          BuildLocalWindowItem(
-              entry->id,
-              static_cast<const sessions::TabRestoreService::Window&>(*entry)
-                  .tabs.size(),
-              ++last_local_model_index_);
+          auto& window =
+              static_cast<const sessions::TabRestoreService::Window&>(*entry);
+          // Generate a window entry if the window contained more than 1 tab.
+          if (window.tabs.size() > 1) {

[sky, 2017/05/08 22:51:36]

We shouldn't need the special case here. Whether you get a tab vs a window
should depend upon how you closed the window. If you close the window, then you
should get a window entry, if you close the last tab in a window then I would
expect a tab entry.

[chrisha, 2017/05/09 15:44:54]

Moved this discussion to the bug, as it's slightly broader scope that in this
code review.

+            BuildLocalWindowItem(entry->id, window.tabs.size(),
+                                 ++last_local_model_index_);
+          } else {
+            // Otherwise, generate a tab entry. This fixes
+            // http://crbug.com/56744.
+            auto& tab = *window.tabs[0];
+            const sessions::SerializedNavigationEntry& current_navigation =
+                tab.navigations.at(tab.current_navigation_index);
+            BuildLocalTabItem(entry->id, current_navigation.title(),
+                              current_navigation.virtual_url(),
+                              ++last_local_model_index_);
+          }
           break;
         }
       }