Add an experimental standalone content suggestions UI.

chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java
index 79910e5857edb491729a8f3a898764bae5f45968..8a290a96734fb3906a81f876440ee482fa62f0f8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/ContextMenuManager.java
@@ -17,7 +17,6 @@ import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ntp.NewTabPageView.NewTabPageManager;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsConfig;
 import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
-import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.ui.base.WindowAndroid.OnCloseContextMenuListener;
 import org.chromium.ui.mojom.WindowOpenDisposition;
 
@@ -43,9 +42,10 @@ public class ContextMenuManager implements OnCloseContextMenuListener {
     public static final int ID_SAVE_FOR_OFFLINE = 3;
     public static final int ID_REMOVE = 4;
 
+    private final Activity mActivity;
     private final NewTabPageManager mManager;
-    private final Tab mTab;
     private final TouchDisableableView mOuterView;
+    private boolean mContextMenuOpen;
 
     /** Defines callback to configure the context menu and respond to user interaction. */
     public interface Delegate {
@@ -65,10 +65,10 @@ public class ContextMenuManager implements OnCloseContextMenuListener {
     /** Interface for a view that can be set to stop responding to touches. */
     public interface TouchDisableableView { void setTouchEnabled(boolean enabled); }
 
-    public ContextMenuManager(
-            NewTabPageManager newTabPageManager, Tab tab, TouchDisableableView outerView) {
+    public ContextMenuManager(Activity activity, NewTabPageManager newTabPageManager,
+            TouchDisableableView outerView) {
+        mActivity = activity;
         mManager = newTabPageManager;
-        mTab = tab;
         mOuterView = outerView;
     }
 
@@ -111,22 +111,19 @@ public class ContextMenuManager implements OnCloseContextMenuListener {
         // or swiping to dismiss an item (eg. https://crbug.com/638854, https://crbug.com/638555,
         // https://crbug.com/636296)
         mOuterView.setTouchEnabled(false);
-
-        mTab.getWindowAndroid().addContextMenuCloseListener(this);
+        mContextMenuOpen = true;
     }
 
     @Override
     public void onContextMenuClosed() {
+        if (!mContextMenuOpen) return;
         mOuterView.setTouchEnabled(true);
-        mTab.getWindowAndroid().removeContextMenuCloseListener(this);
+        mContextMenuOpen = false;
     }
 
     /** Closes the context menu, if open. */
     public void closeContextMenu() {
-        Activity activity = mTab.getWindowAndroid().getActivity().get();
-        if (activity == null) return;
-
-        activity.closeContextMenu();
+        mActivity.closeContextMenu();
     }
 
     private boolean shouldShowItem(@ContextMenuItemId int itemId, Delegate delegate) {