Crop the user-specified profile image for WebUI

components/user_manager/user_image/user_image.cc

 // Copyright 2014 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.
 
 #include "components/user_manager/user_image/user_image.h"
 
 #include "base/trace_event/trace_event.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/codec/jpeg_codec.h"
 
 namespace user_manager {
 
 namespace {
 
 // Default quality for encoding user images.
 const int kDefaultEncodingQuality = 90;
 
-bool EncodeImageSkia(const gfx::ImageSkia& image,
-                     UserImage::Bytes* output) {
-  TRACE_EVENT2("oobe", "EncodeImageSkia",
-               "width", image.width(), "height", image.height());
-  if (image.isNull())
-    return false;
-  const SkBitmap& bitmap = *image.bitmap();
-  SkAutoLockPixels lock_image(bitmap);
-  return gfx::JPEGCodec::Encode(
-      reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0)),
-      gfx::JPEGCodec::FORMAT_SkBitmap,
-      bitmap.width(),
-      bitmap.height(),
-      bitmap.width() * bitmap.bytesPerPixel(),
-      kDefaultEncodingQuality, output);
-}
-
 }  // namespace
 
 // static
+UserImage::Bytes UserImage::Encode(const SkBitmap& bitmap) {
+  TRACE_EVENT2("oobe", "Encode",

[hashimoto, 2016/03/02 07:33:58]

nit: s/Encode/UserImage::Encode/ might be more helpful?

[satorux1, 2016/03/02 08:23:51]

Done.

+               "width", bitmap.width(), "height", bitmap.height());
+  SkAutoLockPixels lock_bitmap(bitmap);
+  Bytes output;
+  if (gfx::JPEGCodec::Encode(
+          reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0)),
+          gfx::JPEGCodec::FORMAT_SkBitmap,
+          bitmap.width(),
+          bitmap.height(),
+          bitmap.width() * bitmap.bytesPerPixel(),
+          kDefaultEncodingQuality, &output)) {
+    return output;

[hashimoto, 2016/03/02 07:33:58]

This line may enjoy NRVO or implicit move so there might be no data copy, but
I'm not so sure about the current status of our codebase.
Are you sure this doesn't result in copying a lot of data?

[satorux1, 2016/03/02 08:23:51]

Good point. Changed it to scoped_ptr<Bytes>

+  } else {
+    return UserImage::Bytes();
+  }
+}
+
+// static
 UserImage UserImage::CreateAndEncode(const gfx::ImageSkia& image) {
-  Bytes image_bytes;
-  if (EncodeImageSkia(image, &image_bytes)) {
+  if (image.isNull())
+    return UserImage(image);

[hashimoto, 2016/03/02 07:33:58]

Just UserImage()?

[satorux1, 2016/03/02 08:23:51]

Done.

+
+  Bytes image_bytes = Encode(*image.bitmap());
+  if (!image_bytes.empty()) {
     UserImage result(image, image_bytes);
     result.MarkAsSafe();
     return result;
   }
   return UserImage(image);
 }
 
 UserImage::UserImage()
     : has_image_bytes_(false),
       is_safe_format_(false) {
@@ skipping 14 matching lines @@
   image_bytes_ = image_bytes;
 }
 
 UserImage::~UserImage() {}
 
 void UserImage::MarkAsSafe() {
   is_safe_format_ = true;
 }
 
 }  // namespace user_manager