Set desired_image_size when decoding images for NTP Tile icons.

chrome/browser/image_decoder.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.
 
 #ifndef CHROME_BROWSER_IMAGE_DECODER_H_
 #define CHROME_BROWSER_IMAGE_DECODER_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequence_checker.h"
 #include "base/sequenced_task_runner.h"
 #include "base/synchronization/lock.h"
 
+namespace gfx {
+class Size;
+}  // namespace gfx
+
 class SkBitmap;
 
 // This is a helper class for decoding images safely in a sandboxed service. To
 // use this, call ImageDecoder::Start(...) or
 // ImageDecoder::StartWithOptions(...) on any thread.
 //
 // ImageRequest::OnImageDecoded or ImageRequest::OnDecodeImageFailed is posted
 // back to the |task_runner_| associated with the ImageRequest.
 //
 // The Cancel() method runs on whichever thread called it.
@@ skipping 48 matching lines @@
   // Calls StartWithOptions() with ImageCodec::DEFAULT_CODEC and
   // shrink_to_fit = false.
   static void Start(ImageRequest* image_request,
                     std::vector<uint8_t> image_data);
   // Deprecated. Use std::vector<uint8_t> version to avoid an extra copy.
   static void Start(ImageRequest* image_request,
                     const std::string& image_data);
 
   // Starts asynchronous image decoding. Once finished, the callback will be
   // posted back to image_request's |task_runner_|.
+  // For images with multiple frames (e.g. ico files), a frame with a size as
+  // close as possible to |desired_image_frame_size| is chosen (tries to take
+  // one in larger size if there's no precise match).

[Mathieu, 2017/03/01 14:36:23]

mention that people can pass gfx::Size() and what happens then.

[tschumann, 2017/03/01 19:40:08]

Done.

   static void StartWithOptions(ImageRequest* image_request,
                                std::vector<uint8_t> image_data,
                                ImageCodec image_codec,
-                               bool shrink_to_fit);
+                               bool shrink_to_fit,
+                               const gfx::Size& desired_image_frame_size);
   // Deprecated. Use std::vector<uint8_t> version to avoid an extra copy.
   static void StartWithOptions(ImageRequest* image_request,
                                const std::string& image_data,
                                ImageCodec image_codec,
                                bool shrink_to_fit);
 
   // Removes all instances of |image_request| from |image_request_id_map_|,
   // ensuring callbacks are not made to the image_request after it is destroyed.
   static void Cancel(ImageRequest* image_request);
 
  private:
   using RequestMap = std::map<int, ImageRequest*>;
 
   ImageDecoder();
   ~ImageDecoder() = delete;
 
   void StartWithOptionsImpl(ImageRequest* image_request,
                             std::vector<uint8_t> image_data,
                             ImageCodec image_codec,
-                            bool shrink_to_fit);
+                            bool shrink_to_fit,
+                            const gfx::Size& desired_image_frame_size);
 
   void CancelImpl(ImageRequest* image_request);
 
   // IPC message handlers.
   void OnDecodeImageSucceeded(const SkBitmap& decoded_image, int request_id);
   void OnDecodeImageFailed(int request_id);
 
   // id to use for the next Start() request that comes in.
   int image_request_id_counter_;
 
   // Map of request id's to ImageRequests.
   RequestMap image_request_id_map_;
 
   // Protects |image_request_id_map_| and |image_request_id_counter_|.
   base::Lock map_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageDecoder);
 };
 
 #endif  // CHROME_BROWSER_IMAGE_DECODER_H_