Add a flag to enable Translate Compact Infobar on Android.

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 0fd1b2383050750f22955e9869957166f861f770..f2c5252983aa8f06050de8a88171f72db321d94c 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -68,6 +68,7 @@
 #include "components/strings/grit/components_strings.h"
 #include "components/sync/driver/sync_driver_switches.h"
 #include "components/tracing/common/tracing_switches.h"
+#include "components/translate/core/browser/translate_infobar_delegate.h"
 #include "components/translate/core/browser/translate_manager.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "components/version_info/version_info.h"
@@ -1605,6 +1606,9 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kPullToRefreshEffectName,
      flag_descriptions::kPullToRefreshEffectDescription, kOsAndroid,
      SINGLE_DISABLE_VALUE_TYPE(switches::kDisablePullToRefreshEffect)},
+    {"translate-compact-infobar", flag_descriptions::kTranslateCompactUIName,
+     flag_descriptions::kTranslateCompactUIDescription, kOsAndroid,
+     FEATURE_VALUE_TYPE(translate::kTranslateCompactUI)},
 #endif  // OS_ANDROID
 #if defined(OS_MACOSX)
     {"enable-translate-new-ux", flag_descriptions::kTranslateNewUxName,