Add --enable-sync-dictionary flag

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 78813c8e565640d940ea0068cf7603bcf496bda9..422e26db61e92af483643906b6aa163f2eba376f 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1195,7 +1195,6 @@ const Experiment kExperiments[] = {
     SINGLE_VALUE_TYPE(switches::kEnableOverscrollHistoryNavigation)
   },
 #endif
-
   {
     "enable-touch-drag-drop",
     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_NAME,
@@ -1231,6 +1230,13 @@ const Experiment kExperiments[] = {
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kEnableDataChannels)
   },
+  {
+    "enable-sync-dictionary",
+    IDS_FLAGS_ENABLE_SYNC_DICTIONARY_NAME,
+    IDS_FLAGS_ENABLE_SYNC_DICTIONARY_DESCRIPTION,
+    kOsWin | kOsCrOS | kOsLinux,
+    SINGLE_VALUE_TYPE(switches::kEnableSyncDictionary)
+  },
 };
 
 const Experiment* experiments = kExperiments;