Announce 'adding' accessibility event when adding a homescreen shortcut.

chrome/android/java/src/org/chromium/chrome/browser/infobar/AppBannerInfoBarAndroid.java

Index: chrome/android/java/src/org/chromium/chrome/browser/infobar/AppBannerInfoBarAndroid.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/infobar/AppBannerInfoBarAndroid.java b/chrome/android/java/src/org/chromium/chrome/browser/infobar/AppBannerInfoBarAndroid.java
index 6528eb9b05b13b396dd832c298c9ba62ed1202da..ea1ee308ceae4c38d6e2851bf3957af92e2ba772 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/infobar/AppBannerInfoBarAndroid.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/infobar/AppBannerInfoBarAndroid.java
@@ -159,6 +159,7 @@ public class AppBannerInfoBarAndroid extends ConfirmInfoBar implements View.OnCl
         } else if (mInstallState == INSTALL_STATE_INSTALLING) {
             text = mIsWebApk ? context.getString(R.string.app_banner_installing_webapk)
                     : context.getString(R.string.app_banner_installing);
+            mButton.announceForAccessibility(text);
             enabled = false;
         } else {
             text = context.getString(R.string.app_banner_open);