Add a PhysicalWebEnvironment class

chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java b/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java
index a71d7d83eedd6715a08f74873322d2c72d6b6a98..da4261e35ef9632c75c1e637492ca95a5717a3cc 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java
@@ -25,6 +25,7 @@ import org.chromium.base.Log;
 import org.chromium.base.ObserverList;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ChromeApplication;
 import org.chromium.chrome.browser.notifications.NotificationConstants;
 import org.chromium.chrome.browser.notifications.NotificationManagerProxy;
 import org.chromium.chrome.browser.notifications.NotificationManagerProxyImpl;
@@ -370,6 +371,13 @@ class UrlManager {
             return;
         }
 
+        // We should only show notifications if there's no other notification-based client.
+        if (PhysicalWebEnvironment
+                .getInstance((ChromeApplication) mContext.getApplicationContext())
+                .hasNotificationBasedClient()) {
+            return;
+        }
+
         // We only call showNotification if the list was empty before because we need to be able to
         // count the number of times we show the OptIn notification.
         if (isUrlListEmptyBefore) {