Refactored touch-events flag test, correcting "enabled" logic.

ui/base/touch/touch_enabled.cc

+// Copyright (c) 2013 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"
+
+namespace ui {
+
+bool AreTouchEventsEnabled() {
+  const CommandLine& command_line = *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();
+  if (touch_enabled_switch != switches::kTouchEventsDisabled)
+    LOG(ERROR) << "Invalid --touch-events option: " << touch_enabled_switch;
+  return false;
+}
+
+}  // namespace ui