[SYNC] Sessions datatype refactor. Most things related to sessions under-the-...

chrome/browser/sessions/session_types.h

Index: chrome/browser/sessions/session_types.h
===================================================================
--- chrome/browser/sessions/session_types.h	(revision 70604)
+++ chrome/browser/sessions/session_types.h	(working copy)
@@ -11,6 +11,7 @@
 
 #include "base/stl_util-inl.h"
 #include "base/string16.h"
+#include "base/time.h"
 #include "chrome/browser/sessions/session_id.h"
 #include "chrome/common/page_transition_types.h"
 #include "gfx/rect.h"
@@ -121,6 +122,10 @@
   // NOTE: when the service is creating SessionTabs, initially this
   // corresponds to TabNavigation.index, not the index in navigations. When done
   // creating though, this is set to the index in navigations.
+  //
+  // NOTE 2: this value can be larger than the size of |navigations|, due to
+  // only valid url's being stored (ie chrome://newtab is not stored). Bounds
+  // checking must be performed before indexing into |navigations|.
   int current_navigation_index;
 
   // True if the tab is pinned.
@@ -129,6 +134,9 @@
   // If non-empty, this tab is an app tab and this is the id of the extension.
   std::string extension_app_id;
 
+  // Timestamp for when this tab was last modified.
+  base::Time timestamp;
+
   std::vector<TabNavigation> navigations;
 
  private:
@@ -168,6 +176,9 @@
   // restore does not attempt to restore them.
   bool is_constrained;
 
+  // Timestamp for when this window was last modified.
+  base::Time timestamp;
+
   // The tabs, ordered by visual order.
   std::vector<SessionTab*> tabs;