Only allow installation of extensions/apps with gallery update url via download from gallery

chrome/common/extensions/extension.h

Index: chrome/common/extensions/extension.h
diff --git a/chrome/common/extensions/extension.h b/chrome/common/extensions/extension.h
index 62bcfc7d29df2f562cec6c067a42a027455c17f8..ffaf1aea55029a80fe5be3f86e27682dc873e1a9 100644
--- a/chrome/common/extensions/extension.h
+++ b/chrome/common/extensions/extension.h
@@ -213,6 +213,10 @@ class Extension {
   // it was explictly turned on via a command line switch).
   static bool AppsAreEnabled();
 
+  // Returns the url prefix for the extension/apps gallery. Can be set via the
+  // --apps-gallery-url switch.
+  static std::string ChromeStoreURL();
+
   // Initialize the extension from a parsed manifest.
   // Usually, the id of an extension is generated by the "key" property of
   // its manifest, but if |require_key| is |false|, a temporary ID will be