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

chrome/browser/ui/prefs/prefs_tab_helper.cc

Index: chrome/browser/ui/prefs/prefs_tab_helper.cc
diff --git a/chrome/browser/ui/prefs/prefs_tab_helper.cc b/chrome/browser/ui/prefs/prefs_tab_helper.cc
index 62396a3d93be1a95c3b1f7acdfa6b34814a9e139..c50f74a3df2ff4579451f3f1e33ef57440c1a2d1 100644
--- a/chrome/browser/ui/prefs/prefs_tab_helper.cc
+++ b/chrome/browser/ui/prefs/prefs_tab_helper.cc
@@ -24,7 +24,6 @@
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_preferences_util.h"
-#include "chrome/browser/ui/zoom/chrome_zoom_level_prefs.h"
 #include "chrome/common/pref_font_webkit_names.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/pref_names_util.h"
@@ -51,6 +50,10 @@
 #include "third_party/icu/source/common/unicode/uscript.h"
 #include "ui/base/l10n/l10n_util.h"
 
+#if !defined(OS_ANDROID)
+#include "chrome/browser/ui/zoom/chrome_zoom_level_prefs.h"
+#endif
+
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
@@ -473,6 +476,7 @@ PrefsTabHelper::PrefsTabHelper(WebContents* contents)
       weak_ptr_factory_(this) {
   PrefService* prefs = profile_->GetPrefs();
   if (prefs) {
+#if !defined(OS_ANDROID)
     // If the tab is in an incognito profile, we track changes in the default
     // zoom level of the parent profile instead.
     Profile* profile_to_track = profile_->GetOriginalProfile();
@@ -486,6 +490,7 @@ PrefsTabHelper::PrefsTabHelper(WebContents* contents)
       default_zoom_level_subscription_ =
           zoom_level_prefs->RegisterDefaultZoomLevelCallback(renderer_callback);
     }
+#endif  // !defined(OS_ANDROID)
 
     PrefWatcher::Get(profile_)->RegisterHelper(this);
   }