Clean up the IconLoader.

chrome/browser/icon_manager.h

 // Copyright (c) 2012 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.
 //
 // Class for finding and caching Windows explorer icons. The IconManager
 // lives on the UI thread but performs icon extraction work on the file thread
 // to avoid blocking the UI thread with potentially expensive COM and disk
 // operations.
 //
 // Terminology
@@ skipping 16 matching lines @@
 //
 // POSIX files don't have associated icons. We query the OS by the file's
 // mime type.
 //
 // The IconManager can be queried in two ways:
 //   1. A quick, synchronous check of its caches which does not touch the disk:
 //      IconManager::LookupIcon()
 //   2. An asynchronous icon load from a file on the file thread:
 //      IconManager::LoadIcon()
 //
-// When using the second (asychronous) method, callers must supply a callback
+// When using the second (asynchronous) method, callers must supply a callback
 // which will be run once the icon has been extracted. The icon manager will
 // cache the results of the icon extraction so that subsequent lookups will be
 // fast.
 //
 // Icon bitmaps returned should be treated as const since they may be referenced
 // by other clients. Make a copy of the icon if you need to modify it.
 
 #ifndef CHROME_BROWSER_ICON_MANAGER_H_
 #define CHROME_BROWSER_ICON_MANAGER_H_
 
 #include <map>
+#include <memory>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "chrome/browser/icon_loader.h"
 #include "ui/gfx/image/image.h"
 
 class IconManager : public IconLoader::Delegate {
  public:
   IconManager();
   ~IconManager() override;
 
   // Synchronous call to examine the internal caches for the icon. Returns the
-  // icon if we have already loaded it, NULL if we don't have it and must load
-  // it via 'LoadIcon'. The returned bitmap is owned by the IconManager and must
-  // not be free'd by the caller. If the caller needs to modify the icon, it
-  // must make a copy and modify the copy.
-  gfx::Image* LookupIconFromFilepath(const base::FilePath& file_name,
+  // icon if we have already loaded it, or null if we don't have it and must
+  // load it via LoadIcon(). The returned bitmap is owned by the IconManager and
+  // must not be free'd by the caller. If the caller needs to modify the icon,
+  // it must make a copy and modify the copy.
+  gfx::Image* LookupIconFromFilepath(const base::FilePath& file_path,
                                      IconLoader::IconSize size);
 
-  typedef base::Callback<void(gfx::Image*)> IconRequestCallback;
+  using IconRequestCallback = base::Callback<void(gfx::Image*)>;
 
   // Asynchronous call to lookup and return the icon associated with file. The
   // work is done on the file thread, with the callbacks running on the thread
   // this function is called.
   //
   // Note:
   // 1. This does *not* check the cache.
   // 2. The returned bitmap pointer is *not* owned by callback. So callback
   //    should never keep it or delete it.
-  // 3. The gfx::Image pointer passed to the callback may be NULL if decoding
+  // 3. The gfx::Image pointer passed to the callback will be null if decoding
   //    failed.
   base::CancelableTaskTracker::TaskId LoadIcon(
       const base::FilePath& file_name,
       IconLoader::IconSize size,
       const IconRequestCallback& callback,
       base::CancelableTaskTracker* tracker);
 
+ private:
   // IconLoader::Delegate interface.
-  bool OnGroupLoaded(IconLoader* loader, const IconGroupID& group) override;
-  bool OnImageLoaded(IconLoader* loader,
-                     gfx::Image* result,
-                     const IconGroupID& group) override;
+  void OnImageLoaded(IconLoader* loader,
+                     std::unique_ptr<gfx::Image> result,
+                     const IconLoader::IconGroup& group) override;
 
- private:
   struct CacheKey {
-    CacheKey(const IconGroupID& group, IconLoader::IconSize size);
+    CacheKey(const IconLoader::IconGroup& group, IconLoader::IconSize size);
 
     // Used as a key in the map below, so we need this comparator.
     bool operator<(const CacheKey &other) const;
 
-    IconGroupID group;
+    IconLoader::IconGroup group;
     IconLoader::IconSize size;
   };
 
-  gfx::Image* LookupIconFromGroup(const IconGroupID& group,
-                                  IconLoader::IconSize size);
-
-  typedef std::map<CacheKey, gfx::Image*> IconMap;
-  IconMap icon_cache_;
-
-  typedef std::map<base::FilePath, IconGroupID> GroupMap;
-  GroupMap group_cache_;
+  std::map<base::FilePath, IconLoader::IconGroup> group_cache_;
+  std::map<CacheKey, std::unique_ptr<gfx::Image>> icon_cache_;
 
   // Asynchronous requests that have not yet been completed.
   struct ClientRequest;
-  typedef std::map<IconLoader*, ClientRequest> ClientRequests;
-  ClientRequests requests_;
+  std::map<IconLoader*, ClientRequest> requests_;
 
   DISALLOW_COPY_AND_ASSIGN(IconManager);
 };
 
 #endif  // CHROME_BROWSER_ICON_MANAGER_H_