Small refactor on InputMethodUtils

Change-Id: Ie4f797508c02abb13c7fe1be162ec4dc18829925

core/java/com/android/internal/inputmethod/InputMethodUtils.java

@@ -57,6 +57,23 @@ public class InputMethodUtils {
         // This utility class is not publicly instantiable.
     }
 
+    // ----------------------------------------------------------------------
+    // Utilities for debug
+    public static String getStackTrace() {
+        final StringBuilder sb = new StringBuilder();
+        try {
+            throw new RuntimeException();
+        } catch (RuntimeException e) {
+            final StackTraceElement[] frames = e.getStackTrace();
+            // Start at 1 because the first frame is here and we don't care about it
+            for (int j = 1; j < frames.length; ++j) {
+                sb.append(frames[j].toString() + "\n");
+            }
+        }
+        return sb.toString();
+    }
+    // ----------------------------------------------------------------------
+
     public static boolean isSystemIme(InputMethodInfo inputMethod) {
         return (inputMethod.getServiceInfo().applicationInfo.flags
                 & ApplicationInfo.FLAG_SYSTEM) != 0;