Introduce Animated Logo to Chrome on Android

components/search_provider_logos/animated_logo_tracker.h

+// 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.
+
+#ifndef COMPONENTS_SEARCH_PROVIDER_LOGOS_ANIMATED_LOGO_TRACKER_H_
+#define COMPONENTS_SEARCH_PROVIDER_LOGOS_ANIMATED_LOGO_TRACKER_H_
+
+#include "base/callback.h"
+#include "net/url_request/url_fetcher_delegate.h"
+#include "url/gurl.h"
+
+namespace net {
+class URLFetcher;
+class URLRequestContextGetter;
+}
+
+namespace search_provider_logos {
+
+typedef base::Callback<void(const std::string&)> AnimatedLogoCallback;
+
+// This class fetches the animated logo for given urls, which are specified in
+// the logo downloaded by LogoTracker.
+class AnimatedLogoTracker : public net::URLFetcherDelegate {
+ public:
+  explicit AnimatedLogoTracker(
+      scoped_refptr<net::URLRequestContextGetter> request_context_getter);
+
+  ~AnimatedLogoTracker() override;
+
+  // Gets the animated logo asynchronously for the given url, and cancels all
+  // previous fetches.
+  void GetAnimatedLogo(const GURL& animated_logo_url,
+                       AnimatedLogoCallback listener);
+
+ private:
+  // Cancels the current fetch, if any, and resets all member variables.
+  void ReturnToIdle();
+
+  // net::URLFetcherDelegate:
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+  // The URLRequestContextGetter used for network requests.
+  scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
+
+  // The URLFetcher currently fetching the logo. NULL when not fetching.
+  scoped_ptr<net::URLFetcher> fetcher_;
+
+  // The callback that will be executed when the animated logo is successfully
+  // downloaded.
+  AnimatedLogoCallback animated_logo_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(AnimatedLogoTracker);
+};
+
+} // namespace search_provider_logos
+
+#endif  // COMPONENTS_SEARCH_PROVIDER_LOGOS_ANIMATED_LOGO_TRACKER_H_