ui: Fix removing a number from the SequentialIDGenerator.

ui/base/sequential_id_generator.cc

 // Copyright (c) 2013 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 "ui/base/sequential_id_generator.h"
 
 #include "base/logging.h"
 
 namespace {
 
@@ skipping 22 matching lines @@
 }
 
 SequentialIDGenerator::~SequentialIDGenerator() {
 }
 
 uint32 SequentialIDGenerator::GetGeneratedID(uint32 number) {
   IDMap::iterator find = number_to_id_.find(number);
   if (find != number_to_id_.end())
     return find->second;
 
-  int id = GetNextAvailableSlot();
+  int id = GetNextAvailableID();
   number_to_id_.insert(std::make_pair(number, id));
   id_to_number_.insert(std::make_pair(id, number));
   return id;
 }
 
 bool SequentialIDGenerator::HasGeneratedIDFor(uint32 number) const {
   return number_to_id_.find(number) != number_to_id_.end();
 }
 
 void SequentialIDGenerator::ReleaseGeneratedID(uint32 id) {
-  if (id < min_available_id_) {
-    min_available_id_ = id;
-    DCHECK_GE(min_available_id_, min_id_);
-  }
+  UpdateNextAvailableIDAfterRelease(id);
   Remove(id, &id_to_number_, &number_to_id_);
 }
 
 void SequentialIDGenerator::ReleaseNumber(uint32 number) {
+  DCHECK_GT(number_to_id_.count(number), 0U);
+  UpdateNextAvailableIDAfterRelease(number_to_id_[number]);
   Remove(number, &number_to_id_, &id_to_number_);
 }
 
-uint32 SequentialIDGenerator::GetNextAvailableSlot() {
+uint32 SequentialIDGenerator::GetNextAvailableID() {
   const uint32 kMaxID = 128;
   while (id_to_number_.count(min_available_id_) > 0 &&
          min_available_id_ < kMaxID) {
     ++min_available_id_;
   }
   if (min_available_id_ >= kMaxID)
     min_available_id_ = min_id_;
   return min_available_id_;
 }
 
+void SequentialIDGenerator::UpdateNextAvailableIDAfterRelease(uint32 id) {
+  if (id < min_available_id_) {
+    min_available_id_ = id;
+    DCHECK_GE(min_available_id_, min_id_);
+  }
+}
+
 }  // namespace ui