Fix a regression in checking the status of the touch events.

ui/base/touch/touch_enabled.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 "ui/base/touch/touch_enabled.h"
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "ui/base/touch/touch_device.h"
+#include "ui/base/ui_base_switches.h"
+#include "ui/events/base_event_utils.h"
+#include "ui/events/event_switches.h"
+
+namespace ui {
+
+namespace {
+
+bool ComputeTouchStatus() {
+  auto* command_line = base::CommandLine::ForCurrentProcess();
+  const std::string touch_enabled_switch =
+      command_line->HasSwitch(switches::kTouchEvents) ?
+          command_line->GetSwitchValueASCII(switches::kTouchEvents) :
+          switches::kTouchEventsAuto;
+
+  if (touch_enabled_switch.empty() ||
+      touch_enabled_switch == switches::kTouchEventsEnabled) {
+    return true;
+  }
+
+  if (touch_enabled_switch == switches::kTouchEventsAuto)
+    return IsTouchDevicePresent();
+
+  DLOG_IF(ERROR, touch_enabled_switch != switches::kTouchEventsDisabled) <<
+      "Invalid --touch-events option: " << touch_enabled_switch;
+  return false;
+}
+
+}  // namespace
+
+bool AreTouchEventsEnabled() {
+  static bool touch_status = ComputeTouchStatus();
+
+#if defined(OS_CHROMEOS)
+  return touch_status && GetTouchEventsCrOsMasterSwitch();
+#else
+  return touch_status;
+#endif  // !defined(OS_CHROMEOS)
+}
+
+}  // namespace ui
+