[TTS] Add an ACK message to SelectWordAroundCaret.

chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.contextualsearch;
 
 import android.os.Handler;
 import android.text.TextUtils;
 
 import org.chromium.base.VisibleForTesting;
@@ skipping 412 matching lines @@
 
         if (selectionStartAdjust == 0 && selectionEndAdjust == 0) return;
         ContentViewCore basePageContentView = getBaseContentView();
         if (basePageContentView != null && basePageContentView.getWebContents() != null) {
             mDidExpandSelection = true;
             basePageContentView.getWebContents().adjustSelectionByCharacterOffset(
                     selectionStartAdjust, selectionEndAdjust);
         }
     }
 
+    /**
+     * Acknowledges that a selectWordAroundCaret action has completed with the give result.
+     * @param didSelect Whether a word was actually selected or not.
+     * @param startAdjust The adjustment to the selection start offset needed to select the word.
+     *        This is typically a negative number (expressed in terms of number of characters).
+     * @param endAdjust The adjustment to the selection end offset needed to select the word.
+     *        This is typically a positive number (expressed in terms of number of characters).
+     */
+    void selectWordAroundCaretAck(boolean didSelect, int startAdjust, int endAdjust) {
+        // TODO(donnd): use startAdjust and endAdjust in upcoming text-extraction CL (started).
+        if (!didSelect) mHandler.handleInvalidTap();
+    }
+
     // ============================================================================================
     // Invalid Tap Notification
     // ============================================================================================
 
     /**
      * Schedules a notification to check if the tap was invalid.
      * When we call selectWordAroundCaret it selects nothing in cases where the tap was invalid.
      * We have no way to know other than scheduling a notification to check later.
      * This allows us to hide the bar when there's no selection.
      */
@@ skipping 151 matching lines @@
         // Starts are inclusive and ends are non-inclusive for both GSAContext & matcher.
         while (matcher.find()) {
             if (startOffset >= matcher.start() && endOffset <= matcher.end()) {
                 return true;
             }
         }
 
         return false;
     }
 }