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

content/browser/web_contents/navigation_entry_impl.h

Index: content/browser/web_contents/navigation_entry_impl.h
diff --git a/content/browser/web_contents/navigation_entry_impl.h b/content/browser/web_contents/navigation_entry_impl.h
index f69cec9a2a879f6ec1c79fb84e314ca62369776e..2918c5429138ab9a0e8b5c6afd27c0af23dc852a 100644
--- a/content/browser/web_contents/navigation_entry_impl.h
+++ b/content/browser/web_contents/navigation_entry_impl.h
@@ -7,6 +7,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
+#include "base/values.h"
 #include "content/browser/site_instance_impl.h"
 #include "content/public/browser/favicon_status.h"
 #include "content/public/browser/global_request_id.h"
@@ -73,6 +74,10 @@ class CONTENT_EXPORT NavigationEntryImpl
   virtual base::Time GetTimestamp() const OVERRIDE;
   virtual void SetCanLoadLocalResources(bool allow) OVERRIDE;
   virtual bool GetCanLoadLocalResources() const OVERRIDE;
+  virtual void SetExtraData(const std::string& key,
+                            const string16& data) OVERRIDE;
+  virtual const bool GetExtraData(const std::string& key,
+                                  string16* out_value) const OVERRIDE;
 
   void set_unique_id(int unique_id) {
     unique_id_ = unique_id;
@@ -259,6 +264,10 @@ class CONTENT_EXPORT NavigationEntryImpl
   // value is not needed after the entry commits and is not persisted.
   bool can_load_local_resources_;
 
+  // Used to store extra data to support browser features.
+  typedef std::map<std::string, string16> ExtraDataMap;
+  ExtraDataMap extra_data_;
+
   // Copy and assignment is explicitly allowed for this class.
 };