[Search] Store and recall search terms using NavigationEntry to improve search term extraction

chrome/browser/sessions/session_types.h

Index: chrome/browser/sessions/session_types.h
diff --git a/chrome/browser/sessions/session_types.h b/chrome/browser/sessions/session_types.h
index c81c75f604d335197fe1010798d040ceb1a30168..8c20de48fcaca8cc4d09b9d5bbd7810e4184a9e0 100644
--- a/chrome/browser/sessions/session_types.h
+++ b/chrome/browser/sessions/session_types.h
@@ -87,6 +87,7 @@ class TabNavigation {
   const GURL& virtual_url() const { return virtual_url_; }
   const string16& title() const { return title_; }
   const std::string& content_state() const { return content_state_; }
+  const string16& search_terms() const { return search_terms_; }
 
   // Converts a set of TabNavigations into a list of NavigationEntrys
   // with sequential page IDs and the given context. The caller owns
@@ -114,6 +115,7 @@ class TabNavigation {
   GURL original_request_url_;
   bool is_overriding_user_agent_;
   base::Time timestamp_;
+  string16 search_terms_;
 };
 
 // SessionTab ----------------------------------------------------------------