Use int32_t for duration property of toast

ash/system/toast/toast_manager.cc

 // Copyright 2016 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 "ash/system/toast/toast_manager.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
 
 namespace ash {
 
 namespace {
 
 // Minimum duration for a toast to be visible (in millisecond).
-uint64_t kMinimumDurationMs = 200;
+int32_t kMinimumDurationMs = 200;
 
 }  // anonymous namespace
 
 ToastManager::ToastManager() : weak_ptr_factory_(this) {}
 
 ToastManager::~ToastManager() {}
 
 void ToastManager::Show(const ToastData& data) {
   const std::string& id = data.id;
   DCHECK(!id.empty());
@@ skipping 38 matching lines @@
   if (!queue_.empty())
     ShowLatest();
 }
 
 void ToastManager::ShowLatest() {
   DCHECK(!overlay_);
 
   const ToastData data = std::move(queue_.front());
   queue_.pop_front();
 
-  uint64_t duration_ms = std::max(data.duration_ms, kMinimumDurationMs);
+  int32_t duration_ms = std::max(data.duration_ms, kMinimumDurationMs);
 
   current_toast_id_ = data.id;
   serial_++;
 
   overlay_.reset(new ToastOverlay(this, data.text));
   overlay_->Show(true);
 
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, base::Bind(&ToastManager::OnDurationPassed,
                             weak_ptr_factory_.GetWeakPtr(), serial_),
       base::TimeDelta::FromMilliseconds(duration_ms));
 }
 
 void ToastManager::OnDurationPassed(int toast_number) {
   if (overlay_ && serial_ == toast_number)
     overlay_->Show(false);
 }
 
 }  // namespace ash