Load offline page if reading list entry takes more than 1s to load.

ios/chrome/browser/reading_list/reading_list_web_state_observer.mm

+// 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 "ios/chrome/browser/reading_list/reading_list_web_state_observer.h"
+
+#import <Foundation/Foundation.h>
+
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/reading_list/reading_list_model.h"
+#include "ios/chrome/browser/reading_list/reading_list_model_factory.h"
+#include "ios/web/public/navigation_item.h"
+#include "ios/web/public/navigation_manager.h"
+
+DEFINE_WEB_STATE_USER_DATA_KEY(ReadingListWebStateObserver);
+
+void ReadingListWebStateObserver::CreateForWebState(
+    web::WebState* web_state,
+    web::BrowserState* browser_state) {
+  DCHECK(browser_state);
+  if (!FromWebState(web_state)) {
+    web_state->SetUserData(UserDataKey(), new ReadingListWebStateObserver(
+                                              web_state, browser_state));
+  }
+}
+
+ReadingListWebStateObserver::~ReadingListWebStateObserver() {}
+
+ReadingListWebStateObserver::ReadingListWebStateObserver(
+    web::WebState* web_state,
+    web::BrowserState* browser_state)
+    : web::WebStateObserver(web_state),
+      web_state_(web_state),
+      reading_list_model_(nullptr) {
+  DCHECK(web_state_);
+
+  ios::ChromeBrowserState* chrome_browser_state =
+      ios::ChromeBrowserState::FromBrowserState(browser_state);
+  reading_list_model_ =
+      ReadingListModelFactory::GetForBrowserState(chrome_browser_state);

[sdefresne, 2016/10/04 13:26:46]

Pass the reading_list_model as a parameter, and remove the browser_state.

+  DCHECK(reading_list_model_);
+}
+
+void ReadingListWebStateObserver::NavigationItemChanged() {
+  timer_.reset();
+}
+
+void ReadingListWebStateObserver::NavigationItemCommitted(
+    const web::LoadCommittedDetails& load_details) {
+  timer_.reset();
+}
+
+void ReadingListWebStateObserver::DidStartLoading() {
+  timer_.reset();
+  web::NavigationManager const* navigation_manager =
+      web_state_->GetNavigationManager();
+  DCHECK(navigation_manager);
+  auto* pending_item = navigation_manager->GetPendingItem();
+  if (pending_item) {
+    NSDictionary* extraData = pending_item->GetExtraData();
+    // TODO(crbug.com/xxxx): Ignore navigations to offline pages.
+    if (extraData[@"readingList"]) {
+      timer_.reset(new base::Timer(false, true));
+      base::TimeDelta delay = base::TimeDelta::FromMilliseconds(1000);
+      timer_->Start(FROM_HERE, delay,
+                    base::Bind(&ReadingListWebStateObserver::
+                                   VerifyIfReadingListEntryStartedLoading,
+                               base::Unretained(this)));
+    }
+  }
+}
+
+void ReadingListWebStateObserver::DidStopLoading() {
+  timer_.reset();
+}
+
+void ReadingListWebStateObserver::PageLoaded(
+    web::PageLoadCompletionStatus load_completion_status) {
+  timer_.reset();
+}
+
+void ReadingListWebStateObserver::WebStateDestroyed() {
+  timer_.reset();
+}
+
+void ReadingListWebStateObserver::VerifyIfReadingListEntryStartedLoading() {
+  web::NavigationManager* navigation_manager =
+      web_state_->GetNavigationManager();
+  web::NavigationItem* pending_item = navigation_manager->GetPendingItem();
+  DCHECK_EQ(ui::PAGE_TRANSITION_READING_LIST,
+            pending_item->GetTransitionType());
+  const GURL& url = pending_item->GetURL();
+  double progress = web_state_->GetLoadingProgress();
+  if (progress < 15) {

[sdefresne, 2016/10/04 13:26:46]

Can you use a named constant instead of "15" so that someone reading the code
understand what is checked here?

+    auto entry = reading_list_model_->GetEntryFromURL(url);
+    if (!entry)
+      return;
+    web::NavigationManager::WebLoadParams params(entry->DistilledURL());
+    params.transition_type = ui::PAGE_TRANSITION_READING_LIST;
+    params.is_renderer_initiated = NO;
+    navigation_manager->LoadURLWithParams(params);
+  }
+}