WebUsb Android chooser UI

chrome/browser/android/usb/web_usb_chooser_service_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/android/usb/web_usb_chooser_service_android.h"
+
+#include <utility>
+
+#include "chrome/browser/ui/android/usb_chooser_android.h"
+#include "content/public/browser/browser_thread.h"
+
+WebUsbChooserServiceAndroid::WebUsbChooserServiceAndroid(
+    content::RenderFrameHost* render_frame_host)
+    : render_frame_host_(render_frame_host) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(render_frame_host_);
+}
+
+WebUsbChooserServiceAndroid::~WebUsbChooserServiceAndroid() {}
+
+void WebUsbChooserServiceAndroid::GetPermission(
+    mojo::Array<device::usb::DeviceFilterPtr> device_filters,
+    const GetPermissionCallback& callback) {
+  usb_chooser_android_.push_back(make_scoped_ptr(new UsbChooserAndroid(

[Yaron, 2016/03/07 21:51:49]

I see these instances are never cleared so it relies on
WebUsbChooserServiceAndroid's lifecycle. That appears to be lazily init'd but
then held on to for some amount of time that I haven't sorted out. I'm worried
about leaks esp since this is holding some objects that would be bad to leak.

[juncai, 2016/03/09 01:26:51]

The WebUsbChooserServiceAndroid object is owned by UsbTabHelper which is the
per-tab owner of USB services provided to render frames within that tab.
UsbTabHelper overrides content::WebContentsObserver::RenderFrameDeleted which
will make sure that WebUsbChooserServiceAndroid is released once a RenderFrame
for |render_frame_host| is deleted.

+      std::move(device_filters), render_frame_host_, callback)));
+}
+
+void WebUsbChooserServiceAndroid::Bind(
+    mojo::InterfaceRequest<device::usb::ChooserService> request) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  bindings_.AddBinding(this, std::move(request));
+}