Add eligibility check when trying to show quick answers.

It was previously gated in context menu. We moved the check to
QuickAnswersController now.

Bug: b/157602163
Test: manual
Change-Id: Ia181ab66bc6fb60c991e59939f037f94b8ec3afc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2219115Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Li Lin <llin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772751}

ash/quick_answers/quick_answers_controller_impl.cc

@@ -49,6 +49,9 @@ void QuickAnswersControllerImpl::MaybeShowQuickAnswers(
     const gfx::Rect& anchor_bounds,
     const std::string& title,
     const Context& context) {
+  if (!is_eligible_)
+    return;
+
   // Cache anchor-bounds and query.
   anchor_bounds_ = anchor_bounds;
   // Initially, title is same as query. Title and query can be overridden based
@@ -84,9 +87,6 @@ void QuickAnswersControllerImpl::MaybeShowQuickAnswers(
 }
 
 void QuickAnswersControllerImpl::DismissQuickAnswers(bool is_active) {
-  if (!is_eligible_)
-    return;
-
   MaybeDismissQuickAnswersConsent();
   quick_answers_ui_controller_->CloseQuickAnswersView();
   quick_answers_client_->OnQuickAnswersDismissed(