Changes semantics of TabSelectedAt. For multi-selection the TabStrip

chrome/browser/tabs/tab_strip_model_observer.h

Index: chrome/browser/tabs/tab_strip_model_observer.h
diff --git a/chrome/browser/tabs/tab_strip_model_observer.h b/chrome/browser/tabs/tab_strip_model_observer.h
index 2eafec03b446819241e10693f6ea2621baa38829..ecd3dd0214f86842c97556dddf706d38e97150b8 100644
--- a/chrome/browser/tabs/tab_strip_model_observer.h
+++ b/chrome/browser/tabs/tab_strip_model_observer.h
@@ -61,10 +61,27 @@ class TabStripModelObserver {
   // happens.
   virtual void TabDeselected(TabContentsWrapper* contents);
 
+  // Invoked any time the selection may have changed. |old_contents| identifies
+  // the previously selected contents. It is entirely possible for the newly
+  // selected tab contents to match |old_contents|. |user_gesture| specifies
+  // whether or not this was done by a user input event (e.g. clicking on a tab,
+  // keystroke) or as a side-effect of some other function.
+  //
+  // This implementation invokes |TabSelectedAt| only if the new and old
+  // contents differ. If you only care about when the selected contents changes,
+  // override |TabSelectedAt|.
+  virtual void TabSelectionChanged(TabStripModel* model,
+                                   TabContentsWrapper* old_contents,
+                                   bool user_gesture);
+
   // The selected TabContents changed from |old_contents| to |new_contents| at
   // |index|. |user_gesture| specifies whether or not this was done by a user
   // input event (e.g. clicking on a tab, keystroke) or as a side-effect of
   // some other function.
+  //
+  // NOTE: this is only invoked when the selected tab contents changes, if you
+  // care about all changes to the selection, override |TabSelectionChanged|
+  // instead.
   virtual void TabSelectedAt(TabContentsWrapper* old_contents,
                              TabContentsWrapper* new_contents,
                              int index,