Allow app banners to trigger on 0 engagement.

chrome/browser/banners/app_banner_manager.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/banners/app_banner_manager.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 345 matching lines @@
 
 void AppBannerManager::DidFinishLoad(
     content::RenderFrameHost* render_frame_host,
     const GURL& validated_url) {
   // Don't start the banner flow unless the main frame has finished loading.
   if (render_frame_host->GetParent())
     return;
 
   load_finished_ = true;
   validated_url_ = validated_url;
+  // Start the pipeline immediately if we aren't using engagement, or if 0
+  // engagement is required.
   if (!AppBannerSettingsHelper::ShouldUseSiteEngagementScore() ||
-      banner_request_queued_) {
+      banner_request_queued_ ||
+      AppBannerSettingsHelper::HasSufficientEngagement(0)) {
+    SiteEngagementObserver::Observe(nullptr);
     banner_request_queued_ = false;
 
     RequestAppBanner(validated_url, false /* is_debug_mode */);
   }
 }
 
 void AppBannerManager::MediaStartedPlaying(const MediaPlayerId& id) {
   active_media_players_.push_back(id);
 }
 
@@ skipping 130 matching lines @@
     // Don't reset |was_canceled_by_page_| yet for metrics purposes.
     OnBannerPromptReply(render_frame_host, request_id,
                         blink::WebAppBannerPromptReply::None, referrer_);
   } else {
     // Log that the prompt request was made for when we get the prompt reply.
     page_requested_prompt_ = true;
   }
 }
 
 }  // namespace banners