Fix task concurrency in components/update_client

components/update_client/update_engine.cc

 // Copyright 2015 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 "components/update_client/update_engine.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/stl_util.h"
@@ skipping 42 matching lines @@
       update_checker_factory_(update_checker_factory),
       crx_downloader_factory_(crx_downloader_factory),
       ping_manager_(ping_manager),
       notify_observers_callback_(notify_observers_callback) {
 }
 
 UpdateEngine::~UpdateEngine() {
   DCHECK(thread_checker_.CalledOnValidThread());
 }
 
-bool UpdateEngine::IsUpdating(const std::string& id) const {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  for (const auto& context : update_contexts_) {
-    const auto& ids = context->ids;
-    const auto it = std::find_if(
-        ids.begin(), ids.end(),
-        [id](const std::string& this_id) { return id == this_id; });
-    if (it != ids.end()) {
-      return true;
-    }
-  }
-  return false;
-}
-
 bool UpdateEngine::GetUpdateState(const std::string& id,
                                   CrxUpdateItem* update_item) {
   DCHECK(thread_checker_.CalledOnValidThread());
   for (const auto& context : update_contexts_) {
     const auto& update_items = context->update_items;
     const auto it = std::find_if(update_items.begin(), update_items.end(),
                                  [id](const CrxUpdateItem* update_item) {
                                    return id == update_item->id;
                                  });
     if (it != update_items.end()) {
@@ skipping 38 matching lines @@
 
   auto callback = update_context->callback;
 
   update_contexts_.erase(update_context);
   delete update_context;
 
   callback.Run(error);
 }
 
 }  // namespace update_client