Allow the app banner installability check to run on page load.

chrome/browser/installable/installable_manager.h

Index: chrome/browser/installable/installable_manager.h
diff --git a/chrome/browser/installable/installable_manager.h b/chrome/browser/installable/installable_manager.h
index 5d56abd0e35b2c22e0a9c43bcf3e4b70d394e9b1..85a52ad4c8e34ef7b02e330280f26ed8f7b29ad1 100644
--- a/chrome/browser/installable/installable_manager.h
+++ b/chrome/browser/installable/installable_manager.h
@@ -16,6 +16,7 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/installable/installable_logging.h"
+#include "chrome/browser/installable/installable_metrics.h"
 #include "content/public/browser/service_worker_context.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
@@ -128,7 +129,14 @@ class InstallableManager
   virtual void GetData(const InstallableParams& params,
                        const InstallableCallback& callback);
 
+  // Called via AppBannerManagerAndroid to record metrics on how often the
+  // installable check is completed when the menu or add to homescreen menu item
+  // is opened on Android.
+  void RecordMenuOpenHistogram();
+  void RecordMenuItemAddToHomescreenHistogram();
+
  private:
+  friend class InstallableManagerBrowserTest;
   friend class InstallableManagerUnitTest;
   FRIEND_TEST_ALL_PREFIXES(InstallableManagerBrowserTest,
                            ManagerBeginsInEmptyState);
@@ -218,6 +226,17 @@ class InstallableManager
   std::unique_ptr<InstallableProperty> installable_;
   std::map<IconParams, IconProperty> icons_;
 
+  // A representation of the progress of the PWA check. This is reset per
+  // navigation and is independent of the caching mechanism, i.e. if a PWA check
+  // is run multiple times, this will be set on the first run.
+  InstallableMetrics::InstallabilityCheckStatus status_;

[benwells, 2017/03/30 08:22:37]

This variable is kinda subtle (e.g. you need to comment). Can you rename it to
something making the subtelty obviuos? E.g. first_run_status_, page_status_, or
something like that.

[dominickn, 2017/03/30 23:42:53]

Done.

+
+  // Counts for the number of queued requests of the menu and add to homescreen
+  // menu item there have been whilst the installable check is awaiting
+  // completion. Used for metrics recording.
+  int menu_opened_count_;
+  int menu_item_add_to_homescreen_count_;
+
   bool is_active_;
 
   base::WeakPtrFactory<InstallableManager> weak_factory_;