Avoid unnecessary copies in ImageDecoder.

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 <memory>
 #include <string>
@@ skipping 61 matching lines @@
     DEFAULT_CODEC = 0,  // Uses WebKit image decoding (via WebImage).
 #if defined(OS_CHROMEOS)
     ROBUST_JPEG_CODEC,  // Restrict decoding to robust jpeg codec.
     ROBUST_PNG_CODEC,  // Restrict decoding to robust PNG codec.
 #endif  // defined(OS_CHROMEOS)
   };
 
   // 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_|.
   static void StartWithOptions(ImageRequest* image_request,
+                               std::vector<uint8_t> image_data,
+                               ImageCodec image_codec,
+                               bool shrink_to_fit);
+  // 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:
   friend struct base::DefaultLazyInstanceTraits<ImageDecoder>;
 
   using RequestMap = std::map<int, ImageRequest*>;
 
   ImageDecoder();
   // It's a reference counted object, so destructor is private.
   ~ImageDecoder() override;
 
   // Sends a request to the sandboxed process to decode the image. Starts
   // batch mode if necessary. If the utility process fails to start,
   // an OnDecodeImageFailed task is posted to image_request's |task_runner_|.
   void DecodeImageInSandbox(int request_id,
-                            const std::vector<unsigned char>& image_data,
+                            std::vector<uint8_t> image_data,
                             ImageCodec image_codec,
                             bool shrink_to_fit);
 
   void StartWithOptionsImpl(ImageRequest* image_request,
-                            const std::string& image_data,
+                            std::vector<uint8_t> image_data,
                             ImageCodec image_codec,
                             bool shrink_to_fit);
   void CancelImpl(ImageRequest* image_request);
 
   // Starts UtilityProcessHost in batch mode and starts |batch_mode_timer_|.
   // If the utility process fails to start, the method resets
   // |utility_process_host_| and returns.
   void StartBatchMode();
 
   // Stops batch mode if no requests have come in since
@@ skipping 34 matching lines @@
   std::unique_ptr<base::DelayTimer> batch_mode_timer_;
 
   // Mojo service connection. Must always be bound/reset and used on the IO
   // thread.
   mojom::ImageDecoderPtr decoder_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageDecoder);
 };
 
 #endif  // CHROME_BROWSER_IMAGE_DECODER_H_