[TTS] Fix a test that's failing with PlzNavigate enabled.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManager.java b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManager.java
index edbf1afa2ac2bd000ff246236949714b7afbb038..9110a764718dd69b1c156fc65be64def9ebe5f5c 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManager.java
@@ -849,6 +849,11 @@ public class ContextualSearchManager implements ContextualSearchManagementDelega
         mSearchPanel.onContextualSearchPrefChanged(isEnabled);
     }
 
+    @Override
+    public void stopPanelContentsNavigation() {
+        mSearchPanel.getContentViewCore().getWebContents().stop();
+    }
+
     // ============================================================================================
     // Observers
     // ============================================================================================
@@ -1098,7 +1103,7 @@ public class ContextualSearchManager implements ContextualSearchManagementDelega
             // Stop loading the page that displays the error to the user.
             if (mSearchPanel.getContentViewCore() != null) {
                 // When running tests the Content View might not exist.
-                mSearchPanel.getContentViewCore().getWebContents().stop();
+                mNetworkCommunicator.stopPanelContentsNavigation();
             }
             mSearchRequest.setHasFailed();
             mSearchRequest.setNormalPriority();