Add support for PNG representation in gfx::Image

ui/gfx/image/image_png.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 "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/image/image_png.h"
+#include "ui/gfx/codec/png_codec.h"
+
+#include <algorithm>
+
+#include "base/logging.h"
+
+namespace gfx {
+
+ImagePNG::ImagePNG(const std::vector<unsigned char>& input)
+  : image_(new base::RefCountedBytes(input)) {
+}
+
+ImagePNG::ImagePNG(const unsigned char* input, size_t input_size)
+  : image_(new base::RefCountedBytes()) {
+    image_->data().assign(input, input + input_size);
+}
+
+ImagePNG::ImagePNG(const ImagePNG& other)
+  : image_(other.image_) {
+}
+
+ImagePNG& ImagePNG::operator=(const ImagePNG& other) {
+  image_ = other.image_;
+  return *this;
+}
+
+ImagePNG::~ImagePNG() {
+}
+
+ImagePNG::ImagePNG() : image_(new base::RefCountedBytes()) {
+}
+
+ImagePNG ImagePNG::FromSkBitmap(const SkBitmap* bitmap) {
+  ImagePNG image;
+  if (!gfx::PNGCodec::EncodeBGRASkBitmap(
+      *bitmap, false, &image.image_->data())) {
+    LOG(WARNING) << "Unable to encode bitmap, returning empty PNG.";
+    image.image_->data().clear();
+  }
+  return image;
+}
+
+bool ImagePNG::empty() const {
+  return image_->data().empty();
+}
+
+const std::vector<unsigned char>& ImagePNG::Image() const {
+  return image_->data();
+}
+
+}  // namespace gfx