Tune web page background fetching

chrome/browser/android/offline_pages/prerendering_loader.cc

 // Copyright 2016 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/android/offline_pages/prerendering_loader.h"
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 #include "net/base/network_change_notifier.h"
 #include "ui/gfx/geometry/size.h"
 
+namespace {
+long kOfflinePageDclDelayMs = 25000;
+long kOfflinePageOnloadDelayMs = 2000;
+}  // namespace
+
+
 namespace offline_pages {
 
 
 // Classifies the appropriate RequestStatus for for the given prerender
 // FinalStatus.
 Offliner::RequestStatus ClassifyFinalStatus(
     prerender::FinalStatus final_status) {
   switch (final_status) {
 
     // Identify aborted/canceled operations
@@ skipping 47 matching lines @@
   content::SessionStorageNamespace* sessionStorageNamespace =
       new_web_contents->GetController().GetDefaultSessionStorageNamespace();
   gfx::Size renderWindowSize = new_web_contents->GetContainerBounds().size();
   bool accepted = adapter_->StartPrerender(
       browser_context_, url, sessionStorageNamespace, renderWindowSize);
   if (!accepted)
     return false;
 
   DCHECK(adapter_->IsActive());
   snapshot_controller_.reset(
-      new SnapshotController(base::ThreadTaskRunnerHandle::Get(), this));
+      new SnapshotController(base::ThreadTaskRunnerHandle::Get(), this,
+                             kOfflinePageDclDelayMs,
+                             kOfflinePageOnloadDelayMs));
   callback_ = callback;
   session_contents_.swap(new_web_contents);
   state_ = State::LOADING;
   return true;
 }
 
 void PrerenderingLoader::StopLoading() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   CancelPrerender();
 }
@@ skipping 128 matching lines @@
 void PrerenderingLoader::CancelPrerender() {
   if (adapter_->IsActive()) {
     adapter_->DestroyActive();
   }
   snapshot_controller_.reset(nullptr);
   session_contents_.reset(nullptr);
   state_ = State::IDLE;
 }
 
 }  // namespace offline_pages