Create platform/mojo and move MojoHelper.h there

third_party/WebKit/Source/modules/webusb/USB.cpp

 // 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 "modules/webusb/USB.h"
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "device/usb/public/interfaces/device.mojom-wtf.h"
 #include "modules/EventTargetModules.h"
 #include "modules/webusb/USBConnectionEvent.h"
 #include "modules/webusb/USBDevice.h"
 #include "modules/webusb/USBDeviceFilter.h"
 #include "modules/webusb/USBDeviceRequestOptions.h"
-#include "platform/MojoHelper.h"
 #include "platform/UserGestureIndicator.h"
+#include "platform/mojo/MojoHelper.h"
 #include "public/platform/ServiceRegistry.h"
 #include "wtf/Functional.h"
 
 namespace usb = device::usb::wtf;
 
 namespace blink {
 namespace {
 
 const char kNoServiceError[] = "USB service unavailable.";
 
@@ skipping 170 matching lines @@
 
 DEFINE_TRACE(USB)
 {
     EventTargetWithInlineData::trace(visitor);
     ContextLifecycleObserver::trace(visitor);
     visitor->trace(m_deviceManagerRequests);
     visitor->trace(m_chooserServiceRequests);
 }
 
 } // namespace blink