Adding @UsedByReflection annotation to 2 classes used by reflection

content/public/android/java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java

Index: content/public/android/java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java b/content/public/android/java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java
index 702690499f7d34ff3032324a1a240feda6623514..fb118a35240e59984eda97b39b8e7b1f3aa0e1d7 100644
--- a/content/public/android/java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java
+++ b/content/public/android/java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java
@@ -87,6 +87,7 @@ public class ThreadedInputConnectionFactory implements ChromiumBaseInputConnecti
         // and we still want to call them for consistency. The setback here is that the only
         // way to distinguish calls from InputMethodManager and from ProxyView is by looking at
         // the call stack.
+        // TODO - avoid using reflection here. See crbug.com/636474
         for (StackTraceElement ste : Thread.currentThread().getStackTrace()) {
             String className = ste.getClassName();
             if (className != null
@@ -239,4 +240,4 @@ public class ThreadedInputConnectionFactory implements ChromiumBaseInputConnecti
         if (mCheckInvalidator != null) mCheckInvalidator.invalidate();
         if (mProxyView != null) mProxyView.onOriginalViewDetachedFromWindow();
     }
-}
+}