Add feature to control showing suggestion summaries.

chrome/browser/flag_descriptions.h

 // 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.
 
 #ifndef CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 #define CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 
 // Includes needed for macros allowing conditional compilation of some strings.
 #include "build/build_config.h"
 #include "build/buildflag.h"
@@ skipping 2588 matching lines @@
 // tiles on the New Tab Page (that originate from synced history).
 extern const char kEnableNtpMostLikelyFaviconsFromServerDescription[];
 
 // Name for the flag to enable the settings entry for content suggestions.
 extern const char kEnableContentSuggestionsSettingsName[];
 
 // Description for the flag to enable the settings entry for content
 // suggestions.
 extern const char kEnableContentSuggestionsSettingsDescription[];
 
+// Name for the flag to enable showing the summary for content suggestions.
+extern const char kEnableContentSuggestionsShowSummaryName[];
+
+// Description for the flag to enable showing the summary for content
+// suggestions.
+extern const char kEnableContentSuggestionsShowSummaryDescription[];
+
 // Name for the flag to enable server-side suggestions on the New Tab Page.
 extern const char kEnableNtpRemoteSuggestionsName[];
 
 // Description for the flag to enable server-side suggestions on the New Tab
 // Page.
 extern const char kEnableNtpRemoteSuggestionsDescription[];
 
 // Name for the flag to enable suggestions for recently viewed tabs, which were
 // captured offline, on the New Tab page.
 extern const char kEnableNtpRecentOfflineTabSuggestionsName[];
@@ skipping 784 matching lines @@
 // a hard-reload.
 extern const char kLocationHardReloadDescription[];
 
 // Name and description for the capture-thumbnail-on-load-finished flag.
 extern const char kCaptureThumbnailOnLoadFinishedName[];
 extern const char kCaptureThumbnailOnLoadFinishedDescription[];
 
 }  // namespace flag_descriptions
 
 #endif  // CHROME_BROWSER_FLAG_DESCRIPTIONS_H_