aura: Make the Linux version of IconLoader not require GTK+.

chrome/browser/icon_loader_linux.cc

+// Copyright (c) 2011 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 "chrome/browser/icon_loader.h"
+
+#include <string>
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/mime_util.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "webkit/glue/image_decoder.h"
+
+using std::string;
+
+void IconLoader::ReadIcon() {
+  int size_pixels = 0;
+  switch (icon_size_) {
+    case IconLoader::SMALL:
+      size_pixels = 16;
+      break;
+    case IconLoader::NORMAL:
+      size_pixels = 32;
+      break;
+    case IconLoader::LARGE:
+      size_pixels = 48;
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  FilePath filename = mime_util::GetMimeIcon(group_, size_pixels);
+  string icon_data;
+  file_util::ReadFileToString(filename, &icon_data);
+
+  webkit_glue::ImageDecoder decoder;
+  scoped_ptr<SkBitmap> bitmap(new SkBitmap());
+  *bitmap = decoder.Decode(
+      reinterpret_cast<const unsigned char*>(icon_data.data()),
+      icon_data.length());
+  if (!bitmap->empty()) {
+    DCHECK_EQ(size_pixels, bitmap->width());
+    DCHECK_EQ(size_pixels, bitmap->height());
+    image_.reset(new gfx::Image(bitmap.release()));
+  } else {
+    LOG(WARNING) << "Unsupported file type or load error: " << filename.value();
+  }
+
+  target_message_loop_->PostTask(
+      FROM_HERE, NewRunnableMethod(this, &IconLoader::NotifyDelegate));
+}