Revert of cc: Add image decode queue functionality to image manager.

cc/tiles/decoded_image_tracker.h

Index: cc/tiles/decoded_image_tracker.h
diff --git a/cc/tiles/decoded_image_tracker.h b/cc/tiles/decoded_image_tracker.h
deleted file mode 100644
index 2d303ee5fe9efa94182e0099131236d2a8c846cd..0000000000000000000000000000000000000000
--- a/cc/tiles/decoded_image_tracker.h
+++ /dev/null
@@ -1,56 +0,0 @@
-// 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 CC_TILES_DECODED_IMAGE_TRACKER_H_
-#define CC_TILES_DECODED_IMAGE_TRACKER_H_
-
-#include <utility>
-#include <vector>
-
-#include "base/bind.h"
-#include "cc/base/cc_export.h"
-#include "cc/tiles/image_controller.h"
-
-class SkImage;
-
-namespace cc {
-
-// This class is the main interface for the rest of the system to request
-// decodes. It is responsible for keeping the decodes locked for a number of
-// frames, specified as |kNumFramesToLock| in the implementation file.
-//
-// Note that it is safe to replace ImageController's cache without doing
-// anything special with this class, since it retains only ids to the decode
-// requests. When defunct ids are then used to try and unlock the image, they
-// are silently ignored.
-class CC_EXPORT DecodedImageTracker {
- public:
-  DecodedImageTracker();
-  ~DecodedImageTracker();
-
-  void QueueImageDecode(sk_sp<const SkImage> image,
-                        const base::Closure& callback);
-  void NotifyFrameFinished();
-
- private:
-  friend class TileManager;
-  friend class DecodedImageTrackerTest;
-
-  void set_image_controller(ImageController* controller) {
-    image_controller_ = controller;
-  }
-
-  void ImageDecodeFinished(const base::Closure& callback,
-                           ImageController::ImageDecodeRequestId id);
-
-  ImageController* image_controller_ = nullptr;
-  std::vector<std::pair<ImageController::ImageDecodeRequestId, int>>
-      locked_images_;
-
-  DISALLOW_COPY_AND_ASSIGN(DecodedImageTracker);
-};
-
-}  // namespace cc
-
-#endif  // CC_TILES_DECODED_IMAGE_TRACKER_H_