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

chrome/browser/ui/toolbar/toolbar_model.h

Index: chrome/browser/ui/toolbar/toolbar_model.h
diff --git a/chrome/browser/ui/toolbar/toolbar_model.h b/chrome/browser/ui/toolbar/toolbar_model.h
index e25e66ed73de3639a2abef574f9dfebe7707b883..b436136f45c1307331f212574942bcf98a99a4b6 100644
--- a/chrome/browser/ui/toolbar/toolbar_model.h
+++ b/chrome/browser/ui/toolbar/toolbar_model.h
@@ -51,6 +51,10 @@ class ToolbarModel {
   // with search terms.
   virtual bool WouldReplaceSearchURLWithSearchTerms() const = 0;
 
+  // Returns search terms if they were set on the NavigationEntry, or empty
+  // string otherwise.
+  virtual string16 GetSearchTermsFromNavigationEntry() const = 0;
+
   // Returns the security level that the toolbar should display.
   virtual SecurityLevel GetSecurityLevel() const = 0;