[SH-Clank] Cleanup tab observer after iframe is deteected.

cleanup() should have also been called after line:79 when iframe is
detected.

Bug: 1157974
Change-Id: I505fa12a82a17da4f3a2ae6dcd239c0f0613be59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2588644Reviewed-by: Kyle Milka <kmilka@chromium.org>
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836733}

chrome/browser/share/android/java/src/org/chromium/chrome/browser/share/link_to_text/LinkToTextCoordinator.java

@@ -70,6 +70,8 @@ public class LinkToTextCoordinator extends EmptyTabObserver {
                     mContext.getResources().getDimensionPixelSize(R.dimen.y_offset));
             toast.show();
         }
+        // After generation results are communicated to users, cleanup to remove tab listener.
+        cleanup();
     }
 
     public void requestSelector() {
@@ -85,7 +87,6 @@ public class LinkToTextCoordinator extends EmptyTabObserver {
             @Override
             public void call(String selector) {
                 onSelectorReady(selector);
-                cleanup();
             }
         });
     }