Reduce the memory usage of bookmarks storage

chrome/browser/bookmarks/chrome_bookmark_client.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/bookmarks/chrome_bookmark_client.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/user_metrics.h"
+#include "base/sys_info.h"
 #include "chrome/browser/favicon/favicon_service_factory.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/bookmarks/browser/bookmark_node.h"
 #include "components/bookmarks/browser/bookmark_storage.h"
 #include "components/bookmarks/managed/managed_bookmark_service.h"
 #include "components/bookmarks/managed/managed_bookmark_util.h"
 #include "components/favicon/core/favicon_util.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/history/core/browser/url_database.h"
 
 #if defined(OS_ANDROID)
 #include "chrome/browser/android/offline_pages/offline_page_bookmark_observer.h"
 #endif
 
+namespace {
+// Optional keys present in MetaInfo maps in bookmark nodes to load in memory.
+const char* const kOptionalMetakeys[] = {"imageData", "pageData"};
+}  // namespace
+
 ChromeBookmarkClient::ChromeBookmarkClient(
     Profile* profile,
     bookmarks::ManagedBookmarkService* managed_bookmark_service)
     : profile_(profile), managed_bookmark_service_(managed_bookmark_service) {}
 
 ChromeBookmarkClient::~ChromeBookmarkClient() {
 }
 
 void ChromeBookmarkClient::Init(bookmarks::BookmarkModel* model) {
   if (managed_bookmark_service_)
@@ skipping 84 matching lines @@
              ? true
              : managed_bookmark_service_->CanSyncNode(node);
 }
 
 bool ChromeBookmarkClient::CanBeEditedByUser(
     const bookmarks::BookmarkNode* node) {
   return !managed_bookmark_service_
              ? true
              : managed_bookmark_service_->CanBeEditedByUser(node);
 }
+
+std::vector<std::string> ChromeBookmarkClient::ExecludedMetaKeys() {
+  std::vector<std::string> optional_keys;
+  // Do not load the image and page data into memory for low-end devices.
+  if (base::SysInfo::IsLowEndDevice()) {
+    optional_keys.insert(optional_keys.end(), std::begin(kOptionalMetakeys),
+                         std::end(kOptionalMetakeys));
+  }
+  return optional_keys;
+}