Remove RuntimeAPIDelegate::GetPreviousVersion.

extensions/browser/extension_registry.h

Index: extensions/browser/extension_registry.h
diff --git a/extensions/browser/extension_registry.h b/extensions/browser/extension_registry.h
index 81bb6f5bef538ecc9f9dab3ebb8355a549edce96..644f421ce33e54fbb51405985d4f4c152a814cce 100644
--- a/extensions/browser/extension_registry.h
+++ b/extensions/browser/extension_registry.h
@@ -20,6 +20,10 @@
 #error "Extensions must be enabled"
 #endif
 
+namespace base {
+class Version;
+}
+
 namespace content {
 class BrowserContext;
 }
@@ -82,6 +86,11 @@ class ExtensionRegistry : public KeyedService {
   std::unique_ptr<ExtensionSet> GenerateInstalledExtensionsSet(
       int include_mask) const;
 
+  // Returns the current version of the extension.
+  // Note that if we are in the process of updating the extension, this will
+  // return the version before update.
+  base::Version GetVersion(const Extension* extension) const;
+
   // The usual observer interface.
   void AddObserver(ExtensionRegistryObserver* observer);
   void RemoveObserver(ExtensionRegistryObserver* observer);