Added pref for snapshot document collapsed state

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index f9cfc8b2d1ce49f8147f74d2bc96f92cb0201c79..a5661db182d68109fe39809af412b08f3ac00499 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -112,6 +112,8 @@
         'browser/android/field_trial_helper.h',
         'browser/android/foreign_session_helper.cc',
         'browser/android/foreign_session_helper.h',
+        'browser/android/new_tab_page_prefs.cc',
+        'browser/android/new_tab_page_prefs.h',
         'browser/android/google_location_settings_helper.h',
         'browser/android/intent_helper.cc',
         'browser/android/intent_helper.h',
@@ -3657,6 +3659,7 @@
             'android/java/src/org/chromium/chrome/browser/favicon/FaviconHelper.java',
             'android/java/src/org/chromium/chrome/browser/FieldTrialHelper.java',
             'android/java/src/org/chromium/chrome/browser/ForeignSessionHelper.java',
+            'android/java/src/org/chromium/chrome/browser/NewTabPagePrefs.java',
             'android/java/src/org/chromium/chrome/browser/IntentHelper.java',
             'android/java/src/org/chromium/chrome/browser/JavascriptAppModalDialog.java',
             'android/java/src/org/chromium/chrome/browser/NavigationPopup.java',