InstantExtended: Transient naventry for preview.

chrome/browser/instant/instant_controller.h

Index: chrome/browser/instant/instant_controller.h
diff --git a/chrome/browser/instant/instant_controller.h b/chrome/browser/instant/instant_controller.h
index 250c31a6c0d10fb64a05141f033f20517b98aff2..397af0d70c523e277443db28f8a8572e255f036b 100644
--- a/chrome/browser/instant/instant_controller.h
+++ b/chrome/browser/instant/instant_controller.h
@@ -36,6 +36,7 @@ class BrowserInstantController;
 }
 
 namespace content {
+class NavigationEntry;
 class WebContents;
 }
 
@@ -222,6 +223,14 @@ class InstantController {
                   int height,
                   InstantSizeUnits units);
 
+  // Copies the loader's NavigationEntry into a transient history entry for the
+  // active tab. Used to update the tab title and make the back button work as
+  // expected when the preview is shown at full height but not yet committed.
+  void SetTransientHistoryEntry();
+
+  // Restores the old transient entry for the active tab, if any.
+  void ResetTransientHistoryEntry();
+
   // Send the omnibox popup bounds to the page.
   void SendPopupBoundsToPage();
 
@@ -324,6 +333,12 @@ class InstantController {
   // MODE_SEARCH_SUGGESTIONS, except in those cases where this is false.
   bool allow_preview_to_show_search_suggestions_;
 
+  // The transient navigation entry associated with the active tab, if any.
+  scoped_ptr<content::NavigationEntry> transient_entry_;
+
+  // True iff Instant has set a transient history entry for the active tab.
+  bool instant_set_transient_entry_;
+
   DISALLOW_COPY_AND_ASSIGN(InstantController);
 };