Remove RuntimeAPIDelegate::GetPreviousVersion.

chrome/browser/extensions/api/runtime/chrome_runtime_api_delegate.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/runtime/chrome_runtime_api_delegate.h"
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 152 matching lines @@
 
 void ChromeRuntimeAPIDelegate::RemoveUpdateObserver(
     extensions::UpdateObserver* observer) {
   if (registered_for_updates_) {
     ExtensionSystem::Get(browser_context_)
         ->extension_service()
         ->RemoveUpdateObserver(observer);
   }
 }
 
-base::Version ChromeRuntimeAPIDelegate::GetPreviousExtensionVersion(
-    const Extension* extension) {
-  // Get the previous version to check if this is an upgrade.
-  ExtensionService* service =
-      ExtensionSystem::Get(browser_context_)->extension_service();
-  const Extension* old = service->GetExtensionById(extension->id(), true);
-  if (old)
-    return *old->version();
-  return base::Version();
-}
-
 void ChromeRuntimeAPIDelegate::ReloadExtension(
     const std::string& extension_id) {
   std::pair<base::TimeTicks, int>& reload_info =
       last_reload_time_[extension_id];
   base::TimeTicks now = base::TimeTicks::Now();
   if (reload_info.first.is_null() ||
       (now - reload_info.first).InMilliseconds() > kFastReloadTime) {
     reload_info.second = 0;
   } else {
     reload_info.second++;
@@ skipping 194 matching lines @@
     const UpdateCheckResult& result) {
   auto it = update_check_info_.find(extension_id);
   if (it == update_check_info_.end())
     return;
   std::vector<UpdateCheckCallback> callbacks;
   it->second.callbacks.swap(callbacks);
   for (const auto& callback : callbacks) {
     callback.Run(result);
   }
 }