Allow the minimum time between banner trigger visits to be varied via field trials.

chrome/browser/banners/app_banner_manager.cc

Index: chrome/browser/banners/app_banner_manager.cc
diff --git a/chrome/browser/banners/app_banner_manager.cc b/chrome/browser/banners/app_banner_manager.cc
index ecbdac5a06e75ce0d16e4d404c051f1ac95447fd..c0b31387eb9d20c882f37569ee789352fe0f7230 100644
--- a/chrome/browser/banners/app_banner_manager.cc
+++ b/chrome/browser/banners/app_banner_manager.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/banners/app_banner_manager.h"
 
+#include "base/metrics/field_trial.h"
+#include "base/strings/string_number_conversions.h"
 #include "chrome/browser/banners/app_banner_data_fetcher.h"
 #include "chrome/browser/banners/app_banner_debug_log.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
@@ -31,6 +33,7 @@ AppBannerManager::AppBannerManager(int icon_size)
     : ideal_icon_size_(icon_size),
       data_fetcher_(nullptr),
       weak_factory_(this) {
+  UpdateMinutesBetweenVisits();
 }
 
 AppBannerManager::AppBannerManager(content::WebContents* web_contents,
@@ -39,6 +42,7 @@ AppBannerManager::AppBannerManager(content::WebContents* web_contents,
       ideal_icon_size_(icon_size),
       data_fetcher_(nullptr),
       weak_factory_(this) {
+  UpdateMinutesBetweenVisits();
 }
 
 AppBannerManager::~AppBannerManager() {
@@ -100,6 +104,14 @@ bool AppBannerManager::IsFetcherActive() {
   return data_fetcher_ != nullptr && data_fetcher_->is_active();
 }
 
+void AppBannerManager::UpdateMinutesBetweenVisits() {

[benwells, 2015/08/24 06:55:52]

Could you just move all this logic into
AppBannerSettingsHelper::UpdateMinutesBetweenVisits or something? Seems like the
settings helper is the thing which should know about the finch trials.

[dominickn, 2015/08/24 07:43:16]

Done.

+  std::string minutes_between_visits =
+      base::FieldTrialList::FindFullName("AppBannersMinutesBetweenVisits");
+  int minimum_minutes;
+  if (base::StringToInt(minutes_between_visits, &minimum_minutes))
+    AppBannerSettingsHelper::SetMinimumMinutesBetweenVisits(minimum_minutes);
+}
+
 void AppBannerManager::DisableSecureSchemeCheckForTesting() {
   gDisableSecureCheckForTesting = true;
 }