Initialize mMode in SubtypeSwitcher and added TODO

Change-Id: If3fa38c5ecf12159cee8d237fa3d5260a9ed66cb
diff --git a/java/src/com/android/inputmethod/latin/SubtypeSwitcher.java b/java/src/com/android/inputmethod/latin/SubtypeSwitcher.java
index a5bfdeb..d696834 100644
--- a/java/src/com/android/inputmethod/latin/SubtypeSwitcher.java
+++ b/java/src/com/android/inputmethod/latin/SubtypeSwitcher.java
@@ -42,6 +42,7 @@
 import java.util.Map;
 
 public class SubtypeSwitcher {
+    // TODO: This should be configurable by resource
     // This flag indicates if we support language switching by swipe on space bar.
     // We may or may not draw the current language on space bar regardless of this flag.
     public static final boolean USE_SPACEBAR_LANGUAGE_SWITCHER = false;
@@ -104,7 +105,8 @@
         mSystemLocale = null;
         mInputLocale = null;
         mInputLocaleStr = null;
-        mMode = null;
+        // Mode is initialized to KEYBOARD_MODE, in case that LatinIME can't obtain currentSubtype
+        mMode = KEYBOARD_MODE;
         mAllEnabledSubtypesOfCurrentInputMethod = null;
         // TODO: Voice input should be created here
         mVoiceInput = null;