Implementation for switching between recently used tabs using ctrl tilde or quoteleft.

chrome/browser/tabs/tab_strip_model.cc

Index: chrome/browser/tabs/tab_strip_model.cc
diff --git a/chrome/browser/tabs/tab_strip_model.cc b/chrome/browser/tabs/tab_strip_model.cc
index ad67ca9d3e06ef64b85e00084891a44a4e224680..16270ee28268c7b33340df5dcaf2aa3f1fe43db0 100644
--- a/chrome/browser/tabs/tab_strip_model.cc
+++ b/chrome/browser/tabs/tab_strip_model.cc
@@ -164,6 +164,11 @@ void TabStripModel::InsertTabContentsAt(int index,
 
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                     TabInsertedAt(contents, index, active));
+  if (active)
+    tab_mru_list_manager_.ActivateContents(contents);
+  else
+    tab_mru_list_manager_.AppendContents(contents);
+
   if (active) {
     TabStripSelectionModel new_model;
     new_model.Copy(selection_model_);
@@ -186,6 +191,8 @@ TabContentsWrapper* TabStripModel::ReplaceTabContentsAt(
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                     TabReplacedAt(this, old_contents, new_contents, index));
 
+  tab_mru_list_manager_.ReplaceContents(old_contents, new_contents);
+
   // When the active tab contents is replaced send out selected notification
   // too. We do this as nearly all observers need to treat a replace of the
   // selected contents as selection changing.
@@ -193,6 +200,7 @@ TabContentsWrapper* TabStripModel::ReplaceTabContentsAt(
     FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                       ActiveTabChanged(old_contents, new_contents,
                                        active_index(), false));
+    tab_mru_list_manager_.ActivateContents(new_contents);
   }
   return old_contents;
 }
@@ -251,8 +259,10 @@ TabContentsWrapper* TabStripModel::DetachTabContentsAt(int index) {
     closing_all_ = true;
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
       TabDetachedAt(removed_contents, index));
+  tab_mru_list_manager_.RemoveContents(removed_contents);
   if (empty()) {
     selection_model_.Clear();
+    tab_mru_list_manager_.ClearContents();
     // TabDetachedAt() might unregister observers, so send |TabStripEmtpy()| in
     // a second pass.
     FOR_EACH_OBSERVER(TabStripModelObserver, observers_, TabStripEmpty());
@@ -757,6 +767,13 @@ void TabStripModel::SelectLastTab() {
   ActivateTabAt(count() - 1, true);
 }
 
+void TabStripModel::SelectNextMRUTab() {
+  TabContentsWrapper* contents = tab_mru_list_manager_.GetNextMRUTab();
+  if (contents) {
+    ActivateTabAt(GetIndexOfTabContents(contents),true);
+  }
+}
+
 void TabStripModel::MoveTabNext() {
   // TODO: this likely needs to be updated for multi-selection.
   int new_index = std::min(active_index() + 1, count() - 1);
@@ -1208,6 +1225,8 @@ void TabStripModel::InternalCloseTab(TabContentsWrapper* contents,
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                     TabClosingAt(this, contents, index));
 
+  tab_mru_list_manager_.RemoveContents(contents);
+
   // Ask the delegate to save an entry for this tab in the historical tab
   // database if applicable.
   if (create_historical_tabs)
@@ -1240,6 +1259,7 @@ void TabStripModel::NotifyIfActiveTabChanged(
                       ActiveTabChanged(old_contents, new_contents,
                                        active_index(),
                                        notify_types == NOTIFY_USER_GESTURE));
+    tab_mru_list_manager_.ActivateContents(new_contents);
     // Activating a discarded tab reloads it, so it is no longer discarded.
     contents_data_[active_index()]->discarded = false;
   }