Use DCHECKs when observing only a single notification.

chrome/browser/bookmarks/bookmark_html_writer.cc

 // Copyright (c) 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/bookmarks/bookmark_html_writer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
@@ skipping 24 matching lines @@
 #include "net/base/escape.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/favicon_size.h"
 
 using bookmarks::BookmarkCodec;
 using bookmarks::BookmarkNode;
 using content::BrowserThread;
 
 namespace {
 
-static BookmarkFaviconFetcher* fetcher = NULL;
+BookmarkFaviconFetcher* g_fetcher = nullptr;
 
 // File header.
 const char kHeader[] =
     "<!DOCTYPE NETSCAPE-Bookmark-file-1>\r\n"
     "<!-- This is an automatically generated file.\r\n"
     "     It will be read and overwritten.\r\n"
     "     DO NOT EDIT! -->\r\n"
     "<META HTTP-EQUIV=\"Content-Type\""
     " CONTENT=\"text/html; charset=UTF-8\">\r\n"
     "<TITLE>Bookmarks</TITLE>\r\n"
@@ skipping 360 matching lines @@
   if (!bookmark_urls_.empty())
     FetchNextFavicon();
   else
     ExecuteWriter();
 }
 
 void BookmarkFaviconFetcher::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  if (chrome::NOTIFICATION_PROFILE_DESTROYED == type && fetcher != NULL) {
-    base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, fetcher);
-    fetcher = NULL;
+  DCHECK_EQ(chrome::NOTIFICATION_PROFILE_DESTROYED, type);
+  if (g_fetcher) {
+    base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, g_fetcher);
+    g_fetcher = nullptr;
   }
 }
 
 void BookmarkFaviconFetcher::ExtractUrls(const BookmarkNode* node) {
   if (node->is_url()) {
     std::string url = node->url().spec();
     if (!url.empty())
       bookmark_urls_.push_back(url);
   } else {
     for (int i = 0; i < node->child_count(); ++i)
       ExtractUrls(node->GetChild(i));
   }
 }
 
 void BookmarkFaviconFetcher::ExecuteWriter() {
   // BookmarkModel isn't thread safe (nor would we want to lock it down
   // for the duration of the write), as such we make a copy of the
   // BookmarkModel using BookmarkCodec then write from that.
   BookmarkCodec codec;
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&Writer::DoWrite,
                  new Writer(codec.Encode(BookmarkModelFactory::GetForProfile(
                                 profile_)),
                             path_, favicons_map_.release(), observer_)));
-  if (fetcher != NULL) {
-    base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, fetcher);
-    fetcher = NULL;
+  if (g_fetcher) {
+    base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, g_fetcher);
+    g_fetcher = nullptr;
   }
 }
 
 bool BookmarkFaviconFetcher::FetchNextFavicon() {
   if (bookmark_urls_.empty()) {
     return false;
   }
   do {
     std::string url = bookmark_urls_.front();
     // Filter out urls that we've already got favicon for.
@@ skipping 36 matching lines @@
 }
 
 namespace bookmark_html_writer {
 
 void WriteBookmarks(Profile* profile,
                     const base::FilePath& path,
                     BookmarksExportObserver* observer) {
   // BookmarkModel isn't thread safe (nor would we want to lock it down
   // for the duration of the write), as such we make a copy of the
   // BookmarkModel using BookmarkCodec then write from that.
-  if (fetcher == NULL) {
-    fetcher = new BookmarkFaviconFetcher(profile, path, observer);
-    fetcher->ExportBookmarks();
+  if (!g_fetcher) {
+    g_fetcher = new BookmarkFaviconFetcher(profile, path, observer);
+    g_fetcher->ExportBookmarks();
   }
 }
 
 }  // namespace bookmark_html_writer