[TTS] Add an ACK message to SelectWordAroundCaret.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
index c16b63a10a95e081fa8507759db6b768d765fb23..2cd3e65bbab65828b747a0dd52a23f127e1a1bd0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
@@ -430,6 +430,19 @@ public class ContextualSearchSelectionController {
         }
     }
 
+    /**
+     * 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
     // ============================================================================================