Make global variable gTimeDeltaForTesting lazily created.

chrome/browser/banners/app_banner_data_fetcher.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_data_fetcher.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/lazy_instance.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/banners/app_banner_debug_log.h"
 #include "chrome/browser/banners/app_banner_metrics.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/manifest/manifest_icon_downloader.h"
 #include "chrome/browser/manifest/manifest_icon_selector.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/render_messages.h"
 #include "components/rappor/rappor_utils.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/service_worker_context.h"
 #include "content/public/browser/storage_partition.h"
 #include "net/base/load_flags.h"
 #include "third_party/WebKit/public/platform/modules/app_banner/WebAppBannerPromptReply.h"
 #include "ui/gfx/screen.h"
 
 namespace {
 
-base::TimeDelta gTimeDeltaForTesting;
+base::LazyInstance<base::TimeDelta> gTimeDeltaForTesting =
+    LAZY_INSTANCE_INITIALIZER;
 int gCurrentRequestID = -1;
 const char kPngExtension[] = ".png";
 
 // The requirement for now is an image/png that is at least 144x144.
 const int kIconMinimumSize = 144;
 bool DoesManifestContainRequiredIcon(const content::Manifest& manifest) {
   for (const auto& icon : manifest.icons) {
     // The type field is optional. If it isn't present, fall back on checking
     // the src extension, and allow the icon if the extension ends with png.
     if (!base::EqualsASCII(icon.type.string(), "image/png") &&
@@ skipping 12 matching lines @@
 
   return false;
 }
 
 }  // anonymous namespace
 
 namespace banners {
 
 // static
 base::Time AppBannerDataFetcher::GetCurrentTime() {
-  return base::Time::Now() + gTimeDeltaForTesting;
+  return base::Time::Now() + gTimeDeltaForTesting.Get();
 }
 
 // static
 void AppBannerDataFetcher::SetTimeDeltaForTesting(int days) {
-  gTimeDeltaForTesting = base::TimeDelta::FromDays(days);
+  gTimeDeltaForTesting.Get() = base::TimeDelta::FromDays(days);
 }
 
 AppBannerDataFetcher::AppBannerDataFetcher(content::WebContents* web_contents,
                                            base::WeakPtr<Delegate> delegate,
                                            int ideal_icon_size_in_dp,
                                            int minimum_icon_size_in_dp,
                                            bool is_debug_mode)
     : WebContentsObserver(web_contents),
       weak_delegate_(delegate),
       ideal_icon_size_in_dp_(ideal_icon_size_in_dp),
@@ skipping 382 matching lines @@
   }
   if (!DoesManifestContainRequiredIcon(manifest)) {
     OutputDeveloperNotShownMessage(web_contents, kManifestMissingSuitableIcon,
                                    is_debug_mode);
     return false;
   }
   return true;
 }
 
 }  // namespace banners