Don't compile code for desktop zoom or GuestViews on mobile platforms.

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/features.h"
 #include "chrome/common/pref_font_webkit_names.h"
@@ skipping 1099 matching lines @@
 
 const char kBackShortcutBubbleShownCount[] =
     "browser.back_shortcut_bubble_shown_count";
 
 #if BUILDFLAG(ENABLE_PLUGINS)
 // Which plugins have been whitelisted manually by the user.
 const char kContentSettingsPluginWhitelist[] =
     "profile.content_settings.plugin_whitelist";
 #endif
 
+#if !defined(OS_ANDROID)
 // Double that indicates the default zoom level.
 const char kPartitionDefaultZoomLevel[] = "partition.default_zoom_level";
 
 // Dictionary that maps hostnames to zoom levels.  Hosts not in this pref will
 // be displayed at the default zoom level.
 const char kPartitionPerHostZoomLevels[] = "partition.per_host_zoom_levels";
 
-#if !defined(OS_ANDROID)
 const char kPinnedTabs[] = "pinned_tabs";
-#endif
+#endif  // !defined(OS_ANDROID)
 
 // Preference to disable 3D APIs (WebGL, Pepper 3D).
 const char kDisable3DAPIs[] = "disable_3d_apis";
 
 const char kEnableDeprecatedWebPlatformFeatures[] =
     "enable_deprecated_web_platform_features";
 
 // Whether to enable hyperlink auditing ("<a ping>").
 const char kEnableHyperlinkAuditing[] = "enable_a_ping";
 
@@ skipping 1400 matching lines @@
     "settings_reset_prompt.last_triggered_for_homepage";
 
 #if defined(OS_ANDROID)
 // Timestamp of the clipboard's last modified time, stored in base::Time's
 // internal format (int64) in local store.  (I.e., this is not a per-profile
 // pref.)
 const char kClipboardLastModifiedTime[] = "ui.clipboard.last_modified_time";
 #endif
 
 }  // namespace prefs