MD History: promote menu button to show clear browsing data in narrow mode

chrome/common/pref_names.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/common/pref_names.h"
 
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "chrome/common/pref_font_webkit_names.h"
 
@@ skipping 900 matching lines @@
 const char kSpeechRecognitionFilterProfanities[] =
     "browser.speechinput_censor_results";
 
 // Boolean controlling whether history saving is disabled.
 const char kSavingBrowserHistoryDisabled[] = "history.saving_disabled";
 
 // Boolean controlling whether deleting browsing and download history is
 // permitted.
 const char kAllowDeletingBrowserHistory[] = "history.deleting_enabled";
 
+#if !defined(OS_ANDROID) && !defined(OS_IOS)
+// Whether the "Click here to clear your browsing data" tooltip promo has been
+// shown on the Material Design History page.
+const char kMdHistoryMenuPromoShown[] = "history.menu_promo_shown";
+#endif
+
 // Boolean controlling whether SafeSearch is mandatory for Google Web Searches.
 const char kForceGoogleSafeSearch[] = "settings.force_google_safesearch";
 
 // Boolean controlling whether Safety Mode is mandatory on YouTube.
 const char kForceYouTubeSafetyMode[] = "settings.force_youtube_safety_mode";
 
 // Boolean controlling whether history is recorded via Session Sync
 // (for supervised users).
 const char kForceSessionSync[] = "settings.history_recorded";
 
@@ skipping 1321 matching lines @@
 const char kOriginTrialPublicKey[] = "origin_trials.public_key";
 
 // A list of origin trial features to disable by policy.
 const char kOriginTrialDisabledFeatures[] = "origin_trials.disabled_features";
 
 // Policy that indicates the state of updates for the binary components.
 const char kComponentUpdatesEnabled[] =
     "component_updates.component_updates_enabled";
 
 }  // namespace prefs