Resize images for hi-dpi based on a custom PNG chunk added by GRIT r78, and roll GRIT r78

ui/gfx/image/image_skia.cc

 // 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.
 
 #include "ui/gfx/image/image_skia.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 
@@ skipping 163 matching lines @@
 ImageSkia::ImageSkia() : storage_(NULL) {
 }
 
 ImageSkia::ImageSkia(ImageSkiaSource* source, const gfx::Size& size)
     : storage_(new internal::ImageSkiaStorage(source, size)) {
   DCHECK(source);
   // No other thread has reference to this, so it's safe to detach the thread.
   DetachStorageFromThread();
 }
 
+ImageSkia::ImageSkia(ImageSkiaSource* source, ui::ScaleFactor scale_factor) {
+  DCHECK(source);
+  ImageSkiaRep image = source->GetImageForScale(scale_factor);
+  if (image.is_null()) {
+    storage_ = NULL;
+    delete source;
+    return;
+  }
+  Size size_in_dip(image.GetWidth(), image.GetHeight());
+  storage_ = new internal::ImageSkiaStorage(source, size_in_dip);

[oshima, 2012/10/10 21:43:29]

Can you add new constructor ImageSkiaStorage(source, scale_factor),
and call FindRepresentation() in there, and initialize size.
(you need to remove const from size_).
Then you can just return ImageSkiaRep() in ResourceBundleImageSource
when the image for given scale factor is not found.

[benrg, 2012/10/11 01:22:02]

Like this? It's a bit awkward because of the failure handling.

+  // No other thread has reference to this, so it's safe to detach the thread.
+  DetachStorageFromThread();

[oshima, 2012/10/10 21:43:29]

DetachStorageFromThread should be called after AddRepresentation

+  AddRepresentation(image);
+}
+
 ImageSkia::ImageSkia(const SkBitmap& bitmap) {
   Init(ImageSkiaRep(bitmap, ui::SCALE_FACTOR_100P));
   // No other thread has reference to this, so it's safe to detach the thread.
   DetachStorageFromThread();
 }
 
 ImageSkia::ImageSkia(const ImageSkiaRep& image_rep) {
   Init(image_rep);
   // No other thread has reference to this, so it's safe to detach the thread.
   DetachStorageFromThread();
@@ skipping 188 matching lines @@
 bool ImageSkia::CanModify() const {
   return !storage_ || storage_->CanModify();
 }
 
 void ImageSkia::DetachStorageFromThread() {
   if (storage_)
     storage_->DetachFromThread();
 }
 
 }  // namespace gfx