Expose a WasLaunchedRecently method using the app banner content setting.

chrome/browser/banners/app_banner_settings_helper.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_BANNERS_APP_BANNER_SETTINGS_HELPER_H_
 #define CHROME_BROWSER_BANNERS_APP_BANNER_SETTINGS_HELPER_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 112 matching lines @@
   static bool HasSufficientEngagement(double total_engagement);
 
   // Record a UMA statistic measuring the minutes between the first visit to the
   // site and the first showing of the banner.
   static void RecordMinutesFromFirstVisitToShow(
       content::WebContents* web_contents,
       const GURL& origin_url,
       const std::string& package_name_or_start_url,
       base::Time time);
 
+  // Returns true if any site under |origin| was launched from homescreen in the
+  // last ten days. This allows services outside app banners to utilise the
+  // content setting that ensures app banners are not shown for sites which ave
+  // already been added to homescreen.
+  static bool WasLaunchedRecently(content::WebContents* web_contents,

[benwells, 2016/07/28 07:47:01]

Its kind of weird that ImportantSites would depend on code in banners/ to see if
something had been launched from the homescreen.

Something to clean up in future CLs.

[dominickn, 2016/07/29 00:34:08]

Yeah, this is definitely something I want to tidy up. It's a mess with the Java
side / native side split. It's unfortunate that the one consistent marker of
homescreen-ness across both is the freshness of this content setting event.

+                                  const GURL& origin_url,
+                                  base::Time now);
+
   // Set the engagement weights assigned to direct and indirect navigations.
   static void SetEngagementWeights(double direct_engagement,
                                    double indirect_engagement);
 
   // Set the minimum number of minutes between banner visits that will
   // trigger a could show banner event. This must be less than the
   // number of minutes in a day, and evenly divide the number of minutes
   // in a day.
   static void SetMinimumMinutesBetweenVisits(unsigned int minutes);
 
@@ skipping 13 matching lines @@
 
   // Returns true if the app banner trigger condition should use the site
   // engagement score instead of the navigation-based heuristic.
   static bool ShouldUseSiteEngagementScore();
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AppBannerSettingsHelper);
 };
 
 #endif  // CHROME_BROWSER_BANNERS_APP_BANNER_SETTINGS_HELPER_H_