Save favicon during reading list distillation

ios/chrome/browser/dom_distiller/web_state_dispatcher_impl.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/dom_distiller/web_state_dispatcher_impl.h"
+
+#include "components/favicon/ios/web_favicon_driver.h"
+#include "components/keyed_service/core/service_access_type.h"
+#include "ios/chrome/browser/bookmarks/bookmark_model_factory.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/favicon/favicon_service_factory.h"
+#include "ios/chrome/browser/history/history_service_factory.h"
+#import "ios/web/public/web_state/web_state.h"
+
+namespace {
+// Delay to download the favicon when the WebState is handed back.
+const int kMaxDelayFavicon = 10;
+}
+
+namespace dom_distiller {
+
+WebStateDispatcherImpl::WebStateDispatcherImpl(web::BrowserState* browser_state)
+    : browser_state_(browser_state), weak_ptr_factory_(this) {}
+WebStateDispatcherImpl::~WebStateDispatcherImpl() {}
+
+web::WebState* WebStateDispatcherImpl::RequestWebState() {
+  const web::WebState::CreateParams web_state_create_params(browser_state_);
+  std::unique_ptr<web::WebState> web_state_unique =
+      web::WebState::Create(web_state_create_params);
+  web::WebState* web_state = web_state_unique.get();
+
+  web_states_[web_state] = std::move(web_state_unique);
+
+  ios::ChromeBrowserState* original_browser_state =
+      ios::ChromeBrowserState::FromBrowserState(browser_state_);
+
+  favicon::WebFaviconDriver::CreateForWebState(
+      web_state,
+      ios::FaviconServiceFactory::GetForBrowserState(
+          original_browser_state, ServiceAccessType::EXPLICIT_ACCESS),
+      ios::HistoryServiceFactory::GetForBrowserState(
+          original_browser_state, ServiceAccessType::EXPLICIT_ACCESS),
+      ios::BookmarkModelFactory::GetForBrowserState(original_browser_state));
+
+  return web_state;
+}
+
+void WebStateDispatcherImpl::ReturnWebState(web::WebState* web_state) {
+  base::WeakPtr<WebStateDispatcherImpl> weak_this =
+      weak_ptr_factory_.GetWeakPtr();
+  dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
+                               (int64_t)(kMaxDelayFavicon * NSEC_PER_SEC)),

[Olivier, 2016/12/16 10:31:31]

Do we need a cleaner on shutdown?

[gambard, 2016/12/16 13:49:19]

On shutdown the WebStateDispatchers should be destroyed and the map also. No
objects should be leaked.
If the callback is called after the object is destroyed the weak_this.get()
should be nil.

Did I miss something?

[Olivier, 2016/12/16 14:10:50]

If the map is destroyed, the web_state is destroyed.
If a distiller_page is using it, is this a problem?

+                 dispatch_get_main_queue(), ^{
+                   WebStateDispatcherImpl* web_state_dispatcher =
+                       weak_this.get();
+                   if (web_state_dispatcher)
+                     web_state_dispatcher->web_states_.erase(web_state);
+                 });
+}
+
+}  // namespace dom_distiller