Implement Android key/value backup

chrome/browser/chrome_browser_main_android.cc

Index: chrome/browser/chrome_browser_main_android.cc
diff --git a/chrome/browser/chrome_browser_main_android.cc b/chrome/browser/chrome_browser_main_android.cc
index b8f38116b8b29964720f25f3744d98285fe5f3ec..2266442d162c1285f6d5861536b76f248d014db8 100644
--- a/chrome/browser/chrome_browser_main_android.cc
+++ b/chrome/browser/chrome_browser_main_android.cc
@@ -90,6 +90,9 @@ void ChromeBrowserMainPartsAndroid::PostProfileInit() {
       content::BrowserThread::FILE, FROM_HERE,
       base::Bind(&DeleteFileTask, bookmark_image_file_path),
       base::TimeDelta::FromMinutes(1));
+  // Start watching the preferences that need to be backed up backup using
+  // Android backup, so that we create a new backup if they change.
+  backup_watcher_.reset(new chrome::android::ChromeBackupWatcher(profile()));
 }
 
 void ChromeBrowserMainPartsAndroid::PreEarlyInitialization() {