Disable an extension when it is upgraded to a version that requires more

chrome/browser/extensions/extension_prefs.h

Index: chrome/browser/extensions/extension_prefs.h
diff --git a/chrome/browser/extensions/extension_prefs.h b/chrome/browser/extensions/extension_prefs.h
index c819bcd18efa5c24ce32adbb175aba63279d1ecf..291556c79b482cd8db487a623b33d2ec47622c67 100644
--- a/chrome/browser/extensions/extension_prefs.h
+++ b/chrome/browser/extensions/extension_prefs.h
@@ -43,6 +43,12 @@ class ExtensionPrefs {
   void OnExtensionUninstalled(const Extension* extension,
                               bool external_uninstall);
 
+  // Returns the state (enabled/disabled) of the given extension.
+  Extension::State GetExtensionState(const std::string& extension_id);
+
+  // Called to change the extension's state when it is enabled/disabled.
+  void SetExtensionState(Extension* extension, Extension::State);
+
   // Returns base extensions install directory.
   const FilePath& install_directory() const { return install_directory_; }
 
@@ -73,6 +79,9 @@ class ExtensionPrefs {
   // Ensures and returns a mutable dictionary for extension |id|'s prefs.
   DictionaryValue* GetOrCreateExtensionPref(const std::string& id);
 
+  // Same as above, but returns NULL if it doesn't exist.
+  DictionaryValue* GetExtensionPref(const std::string& id);
+
   // Checks if kPrefBlacklist is set to true in the DictionaryValue.
   // Return false if the value is false or kPrefBlacklist does not exist.
   // This is used to decide if an extension is blacklisted.
@@ -106,6 +115,10 @@ class InstalledExtensions {
   // the callback.
   void VisitInstalledExtensions(Callback *callback);
 
+  // Same as above, but only for the given extension.
+  void VisitInstalledExtension(const std::string& extension_id,
+                               Callback *callback);
+
  private:
   // A copy of the extensions pref dictionary so that this can be passed
   // around without a dependency on prefs.