Add signals to make callback more reliable

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabActivity.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.customtabs;
 
 import android.content.Intent;
 import android.net.Uri;
 import android.os.IBinder;
 import android.support.customtabs.CustomTabsIntent;
@@ skipping 208 matching lines @@
             ExternalAppId externalId =
                     IntentHandler.determineExternalIntentSource(getPackageName(), getIntent());
             RecordHistogram.recordEnumeratedHistogram("CustomTabs.ClientAppId",
                     externalId.ordinal(), ExternalAppId.INDEX_BOUNDARY.ordinal());
         }
     }
 
     @Override
     public void onStopWithNative() {
         super.onStopWithNative();
+        if (getActivityTab() != null) getActivityTab().hide();

[Benoit L, 2015/08/13 08:18:18]

Should we do something in onPause() rather?

[Yusuf, 2015/08/13 17:28:18]

OK, moved the signal to onPause. Also after talking with dtrainor, switched to
explicitly calling notify from the activity to avoid any side effects.

         setActiveContentHandler(null);
     }
 
     /**
      * Loads the current tab with the given load params. Unlike
      * {@link CustomTab#loadUrlAndTrackFromTimestamp(LoadUrlParams, long)}, this method takes client
      * referrer and extra headers into account.
      */
     private void loadUrlInCurrentTab(LoadUrlParams params, long timeStamp) {
         Intent intent = getIntent();
@@ skipping 125 matching lines @@
 
     /**
      * @return The {@link CustomTabIntentDataProvider} for this {@link CustomTabActivity}. For test
      *         purposes only.
      */
     @VisibleForTesting
     CustomTabIntentDataProvider getIntentDataProvider() {
         return mIntentDataProvider;
     }
 }