Remove NOTIFICATION_EXTENSION_ENABLED.

extensions/browser/events/lazy_event_dispatch_util.cc

+// Copyright 2017 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 "extensions/browser/events/lazy_event_dispatch_util.h"
+
+#include "base/memory/ptr_util.h"
+#include "base/version.h"
+#include "content/public/browser/browser_context.h"
+#include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_prefs.h"
+#include "extensions/browser/extension_registry.h"
+
+namespace extensions {
+
+namespace {
+
+// Previously installed version number.
+const char kPrefPreviousVersion[] = "previous_version";
+
+// A preference key storing the information about an extension that was
+// installed but not loaded. We keep the pending info here so that we can send
+// chrome.runtime.onInstalled event during the extension load.
+const char kPrefPendingOnInstalledEventDispatchInfo[] =
+    "pending_on_installed_event_dispatch_info";
+
+}  // namespace
+
+LazyEventDispatchUtil::LazyEventDispatchUtil(
+    content::BrowserContext* browser_context)
+    : browser_context_(browser_context), extension_registry_observer_(this) {
+  extension_registry_observer_.Add(ExtensionRegistry::Get(browser_context_));
+}
+
+LazyEventDispatchUtil::~LazyEventDispatchUtil() {}
+
+void LazyEventDispatchUtil::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void LazyEventDispatchUtil::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void LazyEventDispatchUtil::OnExtensionLoaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension) {
+  base::Version previous_version;
+  if (ReadPendingOnInstallInfoFromPref(extension->id(), &previous_version)) {
+    for (auto& observer : observers_) {
+      observer.OnExtensionInstalledAndLoaded(browser_context_, extension,
+                                             previous_version);
+    }
+    RemovePendingOnInstallInfoFromPref(extension->id());
+  }
+}
+
+void LazyEventDispatchUtil::OnExtensionUninstalled(
+    content::BrowserContext* browser_context,
+    const Extension* extension,
+    UninstallReason reason) {
+  RemovePendingOnInstallInfoFromPref(extension->id());
+}
+
+void LazyEventDispatchUtil::OnExtensionWillBeInstalled(
+    content::BrowserContext* browser_context,
+    const Extension* extension,
+    bool is_update,
+    const std::string& old_name) {
+  StorePendingOnInstallInfoToPref(extension);
+}
+
+bool LazyEventDispatchUtil::ReadPendingOnInstallInfoFromPref(
+    const ExtensionId& extension_id,
+    base::Version* previous_version) {
+  ExtensionPrefs* prefs = ExtensionPrefs::Get(browser_context_);
+  DCHECK(prefs);
+
+  const base::DictionaryValue* info = nullptr;
+  if (!prefs->ReadPrefAsDictionary(
+          extension_id, kPrefPendingOnInstalledEventDispatchInfo, &info)) {
+    return false;
+  }
+
+  std::string previous_version_string;
+  info->GetString(kPrefPreviousVersion, &previous_version_string);
+  // |previous_version_string| can be empty.
+  *previous_version = base::Version(previous_version_string);
+  return true;
+}
+
+void LazyEventDispatchUtil::RemovePendingOnInstallInfoFromPref(
+    const ExtensionId& extension_id) {
+  ExtensionPrefs* prefs = ExtensionPrefs::Get(browser_context_);
+  DCHECK(prefs);
+
+  prefs->UpdateExtensionPref(extension_id,
+                             kPrefPendingOnInstalledEventDispatchInfo, nullptr);
+}
+
+void LazyEventDispatchUtil::StorePendingOnInstallInfoToPref(
+    const Extension* extension) {
+  ExtensionPrefs* prefs = ExtensionPrefs::Get(browser_context_);
+  DCHECK(prefs);
+
+  // |pending_on_install_info| currently only contains a version string. Instead
+  // of making the pref hold a plain string, we store it as a dictionary value
+  // so that we can add more stuff to it in the future if necessary.
+  auto pending_on_install_info = base::MakeUnique<base::DictionaryValue>();
+  base::Version previous_version = ExtensionRegistry::Get(browser_context_)
+                                       ->GetStoredVersion(extension->id());
+  pending_on_install_info->SetString(
+      kPrefPreviousVersion,
+      previous_version.IsValid() ? previous_version.GetString() : "");

[Devlin, 2017/05/25 21:08:44]

nit: prefer std::string() over ""

[lazyboy, 2017/05/30 23:38:35]

Done.

+  prefs->UpdateExtensionPref(extension->id(),
+                             kPrefPendingOnInstalledEventDispatchInfo,
+                             std::move(pending_on_install_info));
+}
+
+}  // namespace extensions