Cleanup: Pull some browser keep alive functions into its own file.

chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.cc

 // Copyright 2012 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/metro_viewer/chrome_metro_viewer_process_host_aurawin.h"
 
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/host/ash_remote_window_tree_host_win.h"
 #include "ash/shell.h"
 #include "ash/wm/window_positioner.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part_aurawin.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
+#include "chrome/browser/lifetime/browser_keep_alive.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/ui/ash/ash_init.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_navigator.h"
 #include "chrome/browser/ui/browser_navigator_params.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ skipping 36 matching lines @@
   params.host_desktop_type = chrome::HOST_DESKTOP_TYPE_ASH;
   chrome::Navigate(&params);
 }
 
 }  // namespace
 
 ChromeMetroViewerProcessHost::ChromeMetroViewerProcessHost()
     : MetroViewerProcessHost(
           content::BrowserThread::GetMessageLoopProxyForThread(
               content::BrowserThread::IO)) {
-  chrome::IncrementKeepAliveCount();
+  keep_alive_.reset(new browser_lifetime::ScopedKeepAlive);
 }
 
 ChromeMetroViewerProcessHost::~ChromeMetroViewerProcessHost() {
+  DCHECK(!keep_alive_);
 }
 
 void ChromeMetroViewerProcessHost::OnChannelError() {
   // TODO(cpu): At some point we only close the browser. Right now this
   // is very convenient for developing.
   DVLOG(1) << "viewer channel error : Quitting browser";
 
   // Unset environment variable to let breakpad know that metro process wasn't
   // connected.
   ::SetEnvironmentVariableA(env_vars::kMetroConnected, NULL);
 
   // It seems possible that channel is connected, but ASH desktop is not yet
   // created (instance is still NULL) and we receive channel error.
   if (aura::RemoteWindowTreeHostWin::Instance()) {
     aura::RemoteWindowTreeHostWin::Instance()->Disconnected();
 
-    chrome::DecrementKeepAliveCount();
+    keep_alive_.reset();
 
     // If browser is trying to quit, we shouldn't reenter the process.
     // TODO(shrikant): In general there seem to be issues with how AttemptExit
     // reentry works. In future release please clean up related code.
     if (!browser_shutdown::IsTryingToQuit()) {
       CloseOpenAshBrowsers();
       chrome::CloseAsh();
     }
     // Tell the rest of Chrome about it.
     content::NotificationService::current()->Notify(
         chrome::NOTIFICATION_ASH_SESSION_ENDED,
         content::NotificationService::AllSources(),
         content::NotificationService::NoDetails());
     return;
   }
 
-  chrome::DecrementKeepAliveCount();
+  keep_alive_.reset();
 
   // This will delete the MetroViewerProcessHost object. Don't access member
   // variables/functions after this call.
   g_browser_process->platform_part()->OnMetroViewerProcessTerminated();
 }
 
 void ChromeMetroViewerProcessHost::OnChannelConnected(int32 /*peer_pid*/) {
   DVLOG(1) << "ChromeMetroViewerProcessHost::OnChannelConnected: ";
   // Set environment variable to let breakpad know that metro process was
   // connected.
@@ skipping 46 matching lines @@
 void ChromeMetroViewerProcessHost::OnWindowSizeChanged(uint32 width,
                                                        uint32 height) {
   std::vector<ash::DisplayInfo> info_list;
   info_list.push_back(ash::DisplayInfo::CreateFromSpec(
       base::StringPrintf("%dx%d*%f", width, height, gfx::GetDPIScale())));
   ash::Shell::GetInstance()->display_manager()->OnNativeDisplaysChanged(
       info_list);
   aura::RemoteWindowTreeHostWin::Instance()->HandleWindowSizeChanged(width,
                                                                      height);
 }