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

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/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"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/frame_navigate_params.h"
 #include "content/public/common/origin_util.h"
 #include "net/base/load_flags.h"
 #include "ui/gfx/screen.h"
 
 namespace {
 bool gDisableSecureCheckForTesting = false;
 }  // anonymous namespace
 
 namespace banners {
 
 bool AppBannerManager::URLsAreForTheSamePage(const GURL& first,
                                              const GURL& second) {
   return first.GetWithEmptyPath() == second.GetWithEmptyPath() &&
          first.path() == second.path() && first.query() == second.query();
 }
 
 AppBannerManager::AppBannerManager(int icon_size)
     : ideal_icon_size_(icon_size),
       data_fetcher_(nullptr),
       weak_factory_(this) {
+  UpdateMinutesBetweenVisits();
 }
 
 AppBannerManager::AppBannerManager(content::WebContents* web_contents,
                                    int icon_size)
     : content::WebContentsObserver(web_contents),
       ideal_icon_size_(icon_size),
       data_fetcher_(nullptr),
       weak_factory_(this) {
+  UpdateMinutesBetweenVisits();
 }
 
 AppBannerManager::~AppBannerManager() {
   CancelActiveFetcher();
 }
 
 void AppBannerManager::DidCommitProvisionalLoadForFrame(
     content::RenderFrameHost* render_frame_host,
     const GURL& url,
     ui::PageTransition transition_type) {
@@ skipping 41 matching lines @@
   if (data_fetcher_ != nullptr) {
     data_fetcher_->Cancel();
     data_fetcher_ = nullptr;
   }
 }
 
 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;
 }
 
 void AppBannerManager::ForceEngagementWeightsForTesting(
     double direct_engagement,
     double indirect_engagement) {
   AppBannerSettingsHelper::SetEngagementWeights(direct_engagement,
                                                 indirect_engagement);
 }
 
 }  // namespace banners