[Context menu] Attempt to fix NPE in mOnMenuClosed

When ContextMenuHelper#setPopulatorFactory is called, the current
ContextMenuPopulator is destroyed. If a context menu was showing when
dismissed after the populator is destroyed. This is because the
populator is accessed when the context menu is dismissed.

This CL holds a reference to the current context menu and dismisses it
in #setPopulatorFactory.

Bug: 1133172
Change-Id: I879a4278c045c3a4c9028b9b4825b5cd497a5e9e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2446775Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/master@{#813407}

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java

@@ -40,6 +40,7 @@ public class ContextMenuHelper {
     private ContextMenuPopulator mCurrentPopulator;
     private ContextMenuPopulatorFactory mPopulatorFactory;
     private ContextMenuParams mCurrentContextMenuParams;
+    private ContextMenuUi mCurrentContextMenu;
     private WindowAndroid mWindow;
     private Callback<Integer> mCallback;
     private Runnable mOnMenuShown;
@@ -59,6 +60,10 @@ public class ContextMenuHelper {
 
     @CalledByNative
     private void destroy() {
+        if (mCurrentContextMenu != null) {
+            mCurrentContextMenu.dismiss();
+            mCurrentContextMenu = null;
+        }
         if (mCurrentPopulator != null) mCurrentPopulator.onDestroy();
         if (mPopulatorFactory != null) mPopulatorFactory.onDestroy();
         mNativeContextMenuHelper = 0;
@@ -66,6 +71,10 @@ public class ContextMenuHelper {
 
     @CalledByNative
     private void setPopulatorFactory(ContextMenuPopulatorFactory populatorFactory) {
+        if (mCurrentContextMenu != null) {
+            mCurrentContextMenu.dismiss();
+            mCurrentContextMenu = null;
+        }
         if (mCurrentPopulator != null) mCurrentPopulator.onDestroy();
         mCurrentPopulator = null;
         if (mPopulatorFactory != null) mPopulatorFactory.onDestroy();
@@ -112,6 +121,7 @@ public class ContextMenuHelper {
         };
         mOnMenuClosed = (notAbandoned) -> {
             recordTimeToTakeActionHistogram(mSelectedItemBeforeDismiss || notAbandoned);
+            mCurrentContextMenu = null;
             mCurrentPopulator.onMenuClosed();
             if (LensUtils.enableShoppyImageMenuItem()
                     || LensUtils.enableImageChip(mCurrentPopulator.isIncognito())) {
@@ -151,6 +161,7 @@ public class ContextMenuHelper {
 
         final RevampedContextMenuCoordinator menuCoordinator = new RevampedContextMenuCoordinator(
                 topContentOffsetPx, () -> shareImageWithLastShareComponent());
+        mCurrentContextMenu = menuCoordinator;
 
         if (LensUtils.enableImageChip(mCurrentPopulator.isIncognito())) {
             LensAsyncManager lensAsyncManager =

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuUi.java

@@ -39,4 +39,9 @@ public interface ContextMenuUi {
     void displayMenu(WindowAndroid window, WebContents webContents, ContextMenuParams params,
             List<Pair<Integer, ModelList>> items, Callback<Integer> onItemClicked,
             Runnable onMenuShown, Callback<Boolean> onMenuClosed);
+
+    /**
+     * Dismiss the context menu.
+     */
+    void dismiss();
 }

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/RevampedContextMenuCoordinator.java

@@ -89,6 +89,11 @@ public class RevampedContextMenuCoordinator implements ContextMenuUi {
                 onMenuClosed, /* lensAsyncManager=*/null);
     }
 
+    @Override
+    public void dismiss() {
+        dismissDialog();
+    }
+
     // Shows the Context Menu in Chrome with the lens chip (if supported).
     void displayMenuWithLensChip(final WindowAndroid window, WebContents webContents,
             ContextMenuParams params, List<Pair<Integer, ModelList>> items,