Refactor code that defers extension background page loading

chrome/browser/extensions/chrome_process_manager_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/chrome_process_manager_delegate.h"
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/browser.h"
+#include "content/public/browser/notification_service.h"
+#include "extensions/browser/extension_system.h"
+#include "extensions/browser/process_manager.h"
+#include "extensions/common/one_shot_event.h"
+
+#if !defined(OS_ANDROID)
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/common/chrome_switches.h"
+#endif
+
+namespace extensions {
+
+ChromeProcessManagerDelegate::ChromeProcessManagerDelegate() {

[Yoyo Zhou, 2014/07/15 02:13:22]

I like this much better than the terribly unspecific ChromeNotificationObserver.

+  registrar_.Add(this,
+                 chrome::NOTIFICATION_BROWSER_WINDOW_READY,
+                 content::NotificationService::AllSources());
+  registrar_.Add(this,
+                 chrome::NOTIFICATION_PROFILE_CREATED,
+                 content::NotificationService::AllSources());
+  // TODO(jamescook): Move observation of NOTIFICATION_PROFILE_DESTROYED here.
+  // http://crbug.com/392658
+}
+
+ChromeProcessManagerDelegate::~ChromeProcessManagerDelegate() {
+}
+
+bool ChromeProcessManagerDelegate::IsBackgroundPageAllowed(
+    content::BrowserContext* context) const {
+  Profile* profile = static_cast<Profile*>(context);
+
+  // Disallow if the current session is a Guest mode session but the current
+  // browser context is *not* off-the-record. Such context is artificial and
+  // background page shouldn't be created in it.
+  // http://crbug.com/329498
+  return !(profile->IsGuestSession() && !profile->IsOffTheRecord());
+}
+
+bool ChromeProcessManagerDelegate::DeferCreatingStartupBackgroundHosts(
+    content::BrowserContext* context) const {
+  Profile* profile = static_cast<Profile*>(context);
+
+  // The profile may not be valid yet if it is still being initialized.
+  // In that case, defer loading, since it depends on an initialized profile.
+  // Background hosts will be loaded later via NOTIFICATION_PROFILE_CREATED.
+  // http://crbug.com/222473
+  if (!g_browser_process->profile_manager()->IsValidProfile(profile))
+    return true;
+
+#if defined(OS_ANDROID)
+  return false;
+#else
+  // There are no browser windows open and the browser process was
+  // started to show the app launcher. Background hosts will be loaded later
+  // via NOTIFICATION_BROWSER_WINDOW_READY. http://crbug.com/178260
+  return chrome::GetTotalBrowserCountForProfile(profile) == 0 &&
+         CommandLine::ForCurrentProcess()->HasSwitch(switches::kShowAppList);
+#endif
+}
+
+void ChromeProcessManagerDelegate::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {
+    case chrome::NOTIFICATION_BROWSER_WINDOW_READY: {
+      Browser* browser = content::Source<Browser>(source).ptr();
+      OnBrowserWindowReady(browser);
+      break;
+    }
+    case chrome::NOTIFICATION_PROFILE_CREATED: {
+      Profile* profile = content::Source<Profile>(source).ptr();
+      OnProfileCreated(profile);
+      break;
+    }
+
+    default:
+      NOTREACHED();
+  }
+}
+
+void ChromeProcessManagerDelegate::OnBrowserWindowReady(Browser* browser) {
+  Profile* profile = browser->profile();
+  DCHECK(profile);
+
+  // If the extension system isn't ready yet the background hosts will be
+  // created automatically when it is.
+  ExtensionSystem* system = ExtensionSystem::Get(profile);
+  if (!system->ready().is_signaled())
+    return;
+
+  // Inform the process manager for this profile that the window is ready.
+  // We continue to observe the notification in case browser windows open for
+  // a related incognito profile or other regular profiles.
+  ProcessManager* manager = system->process_manager();
+  if (!manager)  // Tests may not have a process manager.
+    return;
+  DCHECK_EQ(profile, manager->GetBrowserContext());
+  manager->MaybeCreateStartupBackgroundHosts();
+
+  // For incognito profiles also inform the original profile's process manager
+  // that the window is ready. This will usually be a no-op because the
+  // original profile's process manager should have been informed when the
+  // non-incognito window opened.
+  if (profile->IsOffTheRecord()) {
+    Profile* original_profile = profile->GetOriginalProfile();
+    ProcessManager* original_manager =
+        ExtensionSystem::Get(original_profile)->process_manager();
+    DCHECK(original_manager);
+    DCHECK_EQ(original_profile, original_manager->GetBrowserContext());
+    original_manager->MaybeCreateStartupBackgroundHosts();
+  }
+}
+
+void ChromeProcessManagerDelegate::OnProfileCreated(Profile* profile) {
+  // Incognito profiles are handled by their original profile.
+  if (profile->IsOffTheRecord())
+    return;
+
+  // The profile can be created before the extension system is ready.
+  ProcessManager* manager = ExtensionSystem::Get(profile)->process_manager();
+  if (!manager)
+    return;
+
+  // The profile might have been initialized asynchronously (in parallel with
+  // extension system startup). Now that initialization is complete the
+  // ProcessManager can load deferred background pages.
+  manager->MaybeCreateStartupBackgroundHosts();
+}
+
+}  // namespace extensions