Changes Mac removable device listing to include all attached USB drives.

chrome/common/extensions/image_writer/image_writer_util_mac.cc

+// Copyright 2014 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/common/extensions/image_writer/image_writer_util_mac.h"
+
+#include <CoreFoundation/CoreFoundation.h>
+
+#include "base/mac/scoped_cftyperef.h"
+#include "base/mac/scoped_ioobject.h"
+
+namespace extensions {
+
+bool IsUsbDevice(io_object_t disk_obj) {
+  io_object_t current_obj = disk_obj;
+  io_object_t parent_obj = 0;
+  // Keep scoped object outside the loop so the object lives to the next
+  // GetParentEntry.
+  base::mac::ScopedIOObject<io_object_t> parent_obj_ref(parent_obj);
+
+  while ((IORegistryEntryGetParentEntry(
+             current_obj, kIOServicePlane, &parent_obj)) == KERN_SUCCESS) {
+    current_obj = parent_obj;
+    parent_obj_ref.reset(parent_obj);
+
+    base::ScopedCFTypeRef<CFStringRef> class_name(
+        IOObjectCopyClass(current_obj));
+    if (!class_name) {
+      LOG(ERROR) << "Could not get object class of IO Registry Entry.";
+      continue;
+    }
+
+    if (CFStringCompare(class_name.get(), CFSTR("IOUSBMassStorageClass"), 0) ==
+        kCFCompareEqualTo) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+}  // namespace extensions