Introduce ThreadedInputConnection behind a switch

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

Index: content/public/android/java/src/org/chromium/content/browser/input/InputMethodManagerWrapper.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/input/InputMethodManagerWrapper.java b/content/public/android/java/src/org/chromium/content/browser/input/InputMethodManagerWrapper.java
index 6a26dbc9c6c65082496000c280bbe6bbbf5e5713..673a3740925a1196b1510e37e49277531ec95aec 100644
--- a/content/public/android/java/src/org/chromium/content/browser/input/InputMethodManagerWrapper.java
+++ b/content/public/android/java/src/org/chromium/content/browser/input/InputMethodManagerWrapper.java
@@ -15,6 +15,9 @@ import android.view.inputmethod.InputMethodManager;
 
 import org.chromium.base.Log;
 
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
 /**
  * Wrapper around Android's InputMethodManager
  */
@@ -88,4 +91,23 @@ public class InputMethodManagerWrapper {
             getInputMethodManager().updateCursorAnchorInfo(view, cursorAnchorInfo);
         }
     }
+
+    /**
+     * Notify that a user took some action with the current input method. Without this call
+     * an input method app may wait longer when the user switches methods within the app.
+     */
+    public void notifyUserAction() {
+        // On N and above, this is not needed.
+        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) return;
+        Log.d(TAG, "notifyUserAction");
+        InputMethodManager manager = getInputMethodManager();
+        try {
+            Method method = InputMethodManager.class.getMethod("notifyUserAction");
+            method.invoke(manager);
+        } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException
+                | InvocationTargetException e) {
+            Log.d(TAG, "notifyUserAction failed");
+            return;
+        }
+    }
 }