Disable WebUSB detector logic on Windows.

chrome/browser/usb/web_usb_detector_unittest.cc

 // Copyright 2015 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 <string>
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/usb/web_usb_detector.h"
 #include "device/base/mock_device_client.h"
 #include "device/usb/mock_usb_device.h"
 #include "device/usb/mock_usb_service.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/notification.h"
 #include "ui/message_center/notification_delegate.h"
 #include "url/gurl.h"
 
+// These tests are disabled because WebUsbDetector::Initialize is a noop on
+// Windows due to jank and hangs caused by enumerating devices.
+// https://crbug.com/656702
+#if !defined(OS_WIN)
 namespace {
 
 // USB device product name.
 const char* kProductName_1 = "Google Product A";
 const char* kProductName_2 = "Google Product B";
 const char* kProductName_3 = "Google Product C";
 
 // USB device landing page.
 const char* kLandingPage_1 = "https://www.google.com/A";
 const char* kLandingPage_2 = "https://www.google.com/B";
@@ skipping 362 matching lines @@
       base::ASCIIToUTF16("Go to www.google.com/C to connect.");
   EXPECT_EQ(expected_message_3, notification_3->message());
   EXPECT_TRUE(notification_3->delegate() != nullptr);
 
   device_client_.usb_service()->RemoveDevice(device_1);
   EXPECT_EQ(nullptr, message_center_->FindVisibleNotificationById(guid_1));
 
   device_client_.usb_service()->RemoveDevice(device_3);
   EXPECT_EQ(nullptr, message_center_->FindVisibleNotificationById(guid_3));
 }
+#endif  // !OS_WIN