Save favicon during reading list distillation

ios/chrome/browser/dom_distiller/favicon_web_state_dispatcher_impl.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_DOM_DISTILLER_FAVICON_WEB_STATE_DISPATCHER_IMPL_H_
+#define IOS_CHROME_BROWSER_DOM_DISTILLER_FAVICON_WEB_STATE_DISPATCHER_IMPL_H_
+
+#include <map>
+#include <memory>
+
+#include "base/memory/weak_ptr.h"
+#include "components/dom_distiller/ios/favicon_web_state_dispatcher.h"
+
+namespace web {
+class BrowserState;
+}
+
+namespace dom_distiller {
+
+// Implementation of the FaviconWebStateDispatcher.
+class FaviconWebStateDispatcherImpl : public FaviconWebStateDispatcher {
+ public:
+  // Constructor with default delay for keeping the WebStates alive.
+  explicit FaviconWebStateDispatcherImpl(web::BrowserState* browser_state);
+  // Constructor for keeping the WebStates alive for |keep_alive_time|.

[sdefresne, 2016/12/20 15:41:00]

Can you add as comment that -1 means to use the default value? Please also state
what is the unit used for keep_alive_time (maybe renamed the variable to
keep_alive_seconds).

[gambard, 2016/12/20 17:11:42]

Done.

+  explicit FaviconWebStateDispatcherImpl(web::BrowserState* browser_state,

[sdefresne, 2016/12/20 15:41:00]

Remove explicit here, it is only for constructor that can be called with just
one argument.

[gambard, 2016/12/20 17:11:42]

Done.

+                                         int keep_alive_time);
+  ~FaviconWebStateDispatcherImpl() override;
+
+  // FaviconWebStateDispatcher implementation.
+  web::WebState* RequestWebState() override;
+  void ReturnWebState(web::WebState* web_state) override;
+
+ private:
+  web::BrowserState* browser_state_;
+  // Map of the WebStates currently alive.
+  std::map<web::WebState*, std::unique_ptr<web::WebState>> web_states_;

[sdefresne, 2016/12/20 15:41:00]

I think it would be simpler to use a std::vector<std::unique_ptr<web::WebState>>
here .

[gambard, 2016/12/20 17:11:42]

Done.

+  // Time during which the WebState will be kept alive after being returned.
+  int keep_alive_time_;
+  base::WeakPtrFactory<FaviconWebStateDispatcherImpl> weak_ptr_factory_;
+};
+
+}  // namespace dom_distiller
+
+#endif  // IOS_CHROME_BROWSER_DOM_DISTILLER_FAVICON_WEB_STATE_DISPATCHER_IMPL_H_