Convert IconManager to use new CancelableTaskTracker

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 29 matching lines @@
 // 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 "base/hash_tables.h"
-#include "chrome/browser/common/cancelable_request.h"
 #include "chrome/browser/icon_loader.h"
+#include "chrome/common/cancelable_task_tracker.h"
 #include "ui/gfx/image/image.h"
 
 class FilePath;
 
-class IconManager : public IconLoader::Delegate,
-                    public CancelableRequestProvider {
+class IconManager : public IconLoader::Delegate {
  public:
   IconManager();
   virtual ~IconManager();
 
   // 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* LookupIcon(const FilePath& file_name,
-                         IconLoader::IconSize size);
+  gfx::Image* LookupIcon(const FilePath& file_name, IconLoader::IconSize size);
 
-  typedef CancelableRequestProvider::Handle Handle;
-  typedef base::Callback<void(Handle, gfx::Image*)> IconRequestCallback;
+  typedef base::Callback<void(gfx::Image*)> IconRequestCallback;
 
   // 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 UI
-  // thread. The return value is the 'request_id' that will be passed to the
-  // client in the callback. Note: this does *not* check the cache.
+  // work is done on the file thread, with the callbacks running on the thread
+  // this function is called.
   //
-  // WATCH OUT: The returned bitmap pointer may be NULL if decoding failed.
-  Handle LoadIcon(const FilePath& file_name,
-                  IconLoader::IconSize size,
-                  CancelableRequestConsumerBase* consumer,
-                  const IconRequestCallback& callback);
+  // 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
+  //    failed.
+  CancelableTaskTracker::TaskId LoadIcon(const FilePath& file_name,
+                                         IconLoader::IconSize size,
+                                         const IconRequestCallback& callback,
+                                         CancelableTaskTracker* tracker);
 
   // IconLoader::Delegate interface.
-  virtual bool OnImageLoaded(IconLoader* source, gfx::Image* result) OVERRIDE;
+  virtual bool OnImageLoaded(IconLoader* loader, gfx::Image* result) OVERRIDE;
 
   // Get the identifying string for the given file. The implementation
   // is in icon_manager_[platform].cc.
   static IconGroupID GetGroupIDFromFilepath(const FilePath& path);
 
  private:
   struct CacheKey {
     CacheKey(const IconGroupID& 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::IconSize size;
   };
 
   typedef std::map<CacheKey, gfx::Image*> IconMap;
   IconMap icon_cache_;
 
-  typedef CancelableRequest<IconRequestCallback> IconRequest;
-
   // Asynchronous requests that have not yet been completed.
   struct ClientRequest;
   typedef std::map<IconLoader*, ClientRequest> ClientRequests;
   ClientRequests requests_;
 
   DISALLOW_COPY_AND_ASSIGN(IconManager);
 };
 
 #endif  // CHROME_BROWSER_ICON_MANAGER_H_