Try my own class

atom/common/api/atom_api_native_image.cc

@@ -17,7 +17,7 @@
 #include "base/files/file_util.h"
 #include "base/strings/pattern.h"
 #include "base/strings/string_util.h"
-#include "chrome/browser/ui/webui/fileicon_source.h"
+#include "atom/common/fileicon_fetcher.h"
 #include "native_mate/dictionary.h"
 #include "native_mate/object_template_builder.h"
 #include "net/base/data_url.h"
@@ -306,7 +306,16 @@ gfx::Size NativeImage::GetSize() {
 void NativeImage::CreateFromFileIcon(v8::Isolate* isolate,
                                      const base::FilePath& path,
                                      const IconLoadedCallback& callback) {
-  callback.Run(CreateEmpty(isolate));
+  IconLoader::IconSize icon_size = IconLoader::IconSize::NORMAL;
+  float scale_factor = 1.0f;
+  auto onready = base::Bind(&NativeImage::OnIconLoaded, isolate, callback);
+  FileIconFetcher::FetchFileIcon(path, scale_factor, icon_size, onready);
+}
+
+void NativeImage::OnIconLoaded(v8::Isolate* isolate,
+                               const IconLoadedCallback& callback,
+                               gfx::Image& image) {
+  callback.Run(Create(isolate, image));
 }
 
 float NativeImage::GetAspectRatio() {

atom/common/api/atom_api_native_image.h

@@ -38,7 +38,7 @@ namespace atom {
 namespace api {
 
 class NativeImage : public mate::Wrappable<NativeImage> {
-using IconLoadedCallback = base::Callback<void(mate::Handle<NativeImage>)>;
+ using IconLoadedCallback = base::Callback<void(mate::Handle<NativeImage>)>;
  public:
   static mate::Handle<NativeImage> CreateEmpty(v8::Isolate* isolate);
   static mate::Handle<NativeImage> Create(
@@ -90,6 +90,9 @@ using IconLoadedCallback = base::Callback<void(mate::Handle<NativeImage>)>;
   gfx::Size GetSize();
   float GetAspectRatio();
 
+  void OnIconLoaded(v8::Isolate* isolate,
+                    const IconLoadedCallback& callback,
+                    gfx::Image& image);
   // Mark the image as template image.
   void SetTemplateImage(bool setAsTemplate);
   // Determine if the image is a template image.

atom/common/fileicon_fetcher.cc

@@ -0,0 +1,76 @@
+// Copyright (c) 2016 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ui/webui/fileicon_source.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/memory/ref_counted_memory.h"
+#include "base/message_loop/message_loop.h"
+#include "base/strings/string_split.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "net/base/escape.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/base/webui/web_ui_util.h"
+#include "ui/gfx/codec/png_codec.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia.h"
+#include "url/gurl.h"
+
+void FileIconFetcher::FetchFileIcon(const base::FilePath& path,
+                                    float scale_factor,
+                                    IconLoader::IconSize icon_size,
+                                    const IconFetchedCallback& callback) {
+  IconManager* im = g_browser_process->icon_manager();
+  gfx::Image* icon = im->LookupIconFromFilepath(path, icon_size);
+
+  if (icon) {
+    scoped_refptr<base::RefCountedBytes> icon_data(new base::RefCountedBytes);
+    gfx::PNGCodec::EncodeBGRASkBitmap(
+        icon->ToImageSkia()->GetRepresentation(scale_factor).sk_bitmap(),
+        false,
+        &icon_data->data());
+
+    callback.Run(icon_data.get());
+  } else {
+    // Attach the ChromeURLDataManager request ID to the history request.
+    IconRequestDetails details;
+    details.callback = callback;
+    details.scale_factor = scale_factor;
+
+    // Icon was not in cache, go fetch it slowly.
+    im->LoadIcon(path,
+                 icon_size,
+                 base::Bind(&FileIconFetcher::OnFileIconDataAvailable, details),
+                 &cancelable_task_tracker_);
+  }
+}
+
+void FileIconFetcher::OnFileIconDataAvailable(const IconRequestDetails& details,
+                                              gfx::Image* icon) {
+  if (icon) {
+    scoped_refptr<base::RefCountedBytes> icon_data(new base::RefCountedBytes);
+    gfx::PNGCodec::EncodeBGRASkBitmap(
+        icon->ToImageSkia()->GetRepresentation(
+            details.scale_factor).sk_bitmap(),
+        false,
+        &icon_data->data());
+
+    details.callback.Run(icon_data.get());
+  } else {
+    details.callback.Run(NULL);
+  }
+}
+
+
+FileIconFetcher::IconRequestDetails::IconRequestDetails() : scale_factor(1.0f) {
+}
+
+FileIconFetcher::IconRequestDetails::IconRequestDetails(
+    const IconRequestDetails& other) = default;
+
+FileIconFetcher::IconRequestDetails::~IconRequestDetails() {
+}

atom/common/fileicon_fetcher.h

@@ -0,0 +1,48 @@
+// Copyright (c) 2016 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_COMMON_API_FILEICON_FETCHER_H_
+#define ATOM_COMMON_API_FILEICON_FETCHER_H_
+
+#include <string>
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/task/cancelable_task_tracker.h"
+#include "chrome/browser/icon_manager.h"
+#include "content/public/browser/url_data_source.h"
+
+namespace gfx {
+class Image;
+}
+
+class FileIconFetcher {
+  using IconFetchedCallback = base::Callback<void(gfx::Image&)>;
+  public:
+  static void FetchFileIcon(const base::FilePath& path,
+                            float scale_factor,
+                            IconLoader::IconSize icon_size,
+                            const IconFetchedCallback& callback);
+
+  private:
+  struct IconRequestDetails {
+    IconRequestDetails();
+    IconRequestDetails(const IconRequestDetails& other);
+    ~IconRequestDetails();
+
+    // The callback to run with the response.
+    IconFetchedCallback callback;
+
+    // The requested scale factor to respond with.
+    float scale_factor;
+  };
+  // Called when favicon data is available from the history backend.
+  static void OnFileIconDataAvailable(const IconRequestDetails& details,
+                                      gfx::Image* icon);
+
+  // Tracks tasks requesting file icons.
+  base::CancelableTaskTracker cancelable_task_tracker_;
+};
+
+#endif  // ATOM_COMMON_API_FILEICON_FETCHER_H_