Remove unneeded IconLoader::image_

chrome/browser/icon_loader_mac.mm

Index: chrome/browser/icon_loader_mac.mm
diff --git a/chrome/browser/icon_loader_mac.mm b/chrome/browser/icon_loader_mac.mm
index dd94e9fe7eab1e17b1ead5efb7766cbd0466802e..392f2b22b2535953baf0b4b6b1f66e169aec7f91 100644
--- a/chrome/browser/icon_loader_mac.mm
+++ b/chrome/browser/icon_loader_mac.mm
@@ -8,6 +8,7 @@
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
+#include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/thread.h"
@@ -30,9 +31,11 @@ void IconLoader::ReadIcon() {
   NSWorkspace* workspace = [NSWorkspace sharedWorkspace];
   NSImage* icon = [workspace iconForFileType:group];
 
+  std::unique_ptr<gfx::Image> image;
+
   if (icon_size_ == ALL) {
     // The NSImage already has all sizes.
-    image_.reset(new gfx::Image([icon retain]));
+    image = base::MakeUnique<gfx::Image>([icon retain]);
   } else {
     NSSize size = NSZeroSize;
     switch (icon_size_) {
@@ -48,11 +51,11 @@ void IconLoader::ReadIcon() {
     gfx::ImageSkia image_skia(gfx::ImageSkiaFromResizedNSImage(icon, size));
     if (!image_skia.isNull()) {
       image_skia.MakeThreadSafe();
-      image_.reset(new gfx::Image(image_skia));
+      image = base::MakeUnique<gfx::Image>(image_skia);
     }
   }
 
   target_task_runner_->PostTask(
-      FROM_HERE, base::Bind(callback_, base::Passed(&image_), group_));
+      FROM_HERE, base::Bind(callback_, base::Passed(&image), group_));
   delete this;
 }