WebUSB Android chooser should be closed when "Get help" button is pressed

chrome/browser/ui/android/usb_chooser_dialog_android.cc

 // Copyright 2016 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/browser/ui/android/usb_chooser_dialog_android.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 148 matching lines @@
 void UsbChooserDialogAndroid::OnDialogCancelled(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj) {
   Cancel();
 }
 
 void UsbChooserDialogAndroid::LoadUsbHelpPage(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj) {
   OpenUrl(chrome::kChooserUsbOverviewURL);
+  Cancel();
 }
 
 // Get a list of devices that can be shown in the chooser bubble UI for
 // user to grant permsssion.
 void UsbChooserDialogAndroid::GotUsbDeviceList(
     const std::vector<scoped_refptr<device::UsbDevice>>& devices) {
   for (const auto& device : devices) {
     if (device::UsbDeviceFilter::MatchesAny(device, filters_) &&
         FindInWebUsbAllowedOrigins(
             device->webusb_allowed_origins(),
@@ skipping 34 matching lines @@
       ->OpenURL(content::OpenURLParams(GURL(url), content::Referrer(),
                                        NEW_FOREGROUND_TAB,
                                        ui::PAGE_TRANSITION_AUTO_TOPLEVEL,
                                        false));  // is_renderer_initiated
 }
 
 // static
 bool UsbChooserDialogAndroid::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }