customtabs: Prevent the app menu window from leaking when finishing the activity.

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java
index 0f59feee39018f74a3d25a16fbaa562e0e9ac6ad..e9bf7e02ba00c97e2ff87edccdd30759da2a8af8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.java
@@ -524,6 +524,9 @@ public class CustomTabActivity extends ChromeActivity {
 
     @Override
     public void finish() {
+        // Prevent the menu window from leaking.
+        if (getAppMenuHandler() != null) getAppMenuHandler().hideAppMenu();
+
         super.finish();
         if (mIntentDataProvider != null && mIntentDataProvider.shouldAnimateOnFinish()) {
             mShouldOverridePackage = true;