Make Interaction Media Features MQ dynamic on Windows.

content/browser/renderer_host/input/input_device_change_observer.cc

+// Copyright 2017 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 "content/browser/renderer_host/input/input_device_change_observer.h"
+#include "base/trace_event/trace_event.h"
+#include "content/public/common/web_preferences.h"
+
+#if defined(OS_WIN)
+#include "ui/events/devices/input_device_observer_win.h"
+#endif
+
+namespace content {
+
+InputDeviceChangeObserver::InputDeviceChangeObserver(RenderViewHost* rvh) {
+  render_view_host_ = rvh;
+#if defined(OS_WIN)
+  ui::InputDeviceObserverWin::GetInstance()->AddObserver(this);
+#endif
+}
+
+InputDeviceChangeObserver::~InputDeviceChangeObserver() {
+#if defined(OS_WIN)
+  ui::InputDeviceObserverWin::GetInstance()->RemoveObserver(this);
+#endif
+  render_view_host_ = nullptr;
+}
+
+void InputDeviceChangeObserver::OnTouchscreenDeviceConfigurationChanged() {
+  NotifyRenderViewHost();
+}
+
+void InputDeviceChangeObserver::OnKeyboardDeviceConfigurationChanged() {
+  NotifyRenderViewHost();
+}
+
+void InputDeviceChangeObserver::OnMouseDeviceConfigurationChanged() {
+  NotifyRenderViewHost();
+}
+
+void InputDeviceChangeObserver::OnTouchpadDeviceConfigurationChanged() {
+  NotifyRenderViewHost();
+}
+
+void InputDeviceChangeObserver::NotifyRenderViewHost() {
+  WebPreferences prefs = render_view_host_->GetWebkitPreferences();
+  int available_pointer_types, available_hover_types;
+  std::tie(available_pointer_types, available_hover_types) =
+      ui::GetAvailablePointerAndHoverTypes();
+  bool input_device_changed =
+      prefs.available_pointer_types != available_pointer_types ||
+      prefs.available_hover_types != available_hover_types;
+
+  if (input_device_changed) {
+    TRACE_EVENT0("input", "InputDeviceChangeObserver::NotifyRendererViewHost");
+    render_view_host_->OnWebkitPreferencesChanged();
+  }
+}
+
+}  // namespace content