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

ui/events/base_event_utils.cc

Index: ui/events/base_event_utils.cc
diff --git a/ui/events/base_event_utils.cc b/ui/events/base_event_utils.cc
index 622d2f206179bf0886a1ffc7110366ab16e4abbc..f81c21dcbe90a4acf442e6a9acc89b319e9b71fe 100644
--- a/ui/events/base_event_utils.cc
+++ b/ui/events/base_event_utils.cc
@@ -7,6 +7,7 @@
 #include "base/atomic_sequence_num.h"
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "ui/base/touch/touch_device.h"

[sadrul, 2015/11/17 22:32:05]

This is in the ui_base target, which depends on the events_base target, which
base_event_utils.cc belongs to. This introduces a dependency cycle, and we
cannot have it.

 #include "ui/events/event_constants.h"
 #include "ui/events/event_switches.h"
 
@@ -21,9 +22,9 @@ bool touch_events_enabled = true;
 const int kSystemKeyModifierMask = EF_ALT_DOWN | EF_COMMAND_DOWN;
 #else
 const int kSystemKeyModifierMask = EF_ALT_DOWN;
+#endif  // defined(OS_CHROMEOS)
 
-// Retrieves the status of the touch screen events from the command line on Non-
-// ChromeOS platforms.
+// Retrieves the status of the touch screen events from the command line.
 bool ComputeTouchStatus() {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
@@ -33,20 +34,18 @@ bool ComputeTouchStatus() {
       switches::kTouchEventsAuto;
 
   if (touch_enabled_switch.empty() ||
-      touch_enabled_switch == switches::kTouchEventsEnabled ||
-      touch_enabled_switch == switches::kTouchEventsAuto) {
+      touch_enabled_switch == switches::kTouchEventsEnabled) {
     return true;
   }
 
-  if (touch_enabled_switch == switches::kTouchEventsDisabled)
-    return false;
+  if (touch_enabled_switch == switches::kTouchEventsAuto)
+    return IsTouchDevicePresent();
 
-  LOG(ERROR) << "Invalid --touch-events option: " << touch_enabled_switch;
+  if (touch_enabled_switch != switches::kTouchEventsDisabled)
+    LOG(ERROR) << "Invalid --touch-events option: " << touch_enabled_switch;
   return false;
 }
 
-#endif  // defined(OS_CHROMEOS)
-
 }  // namespace
 
 base::StaticAtomicSequenceNumber g_next_event_id;
@@ -77,11 +76,12 @@ void SetTouchEventsEnabled(bool enabled) {
 #endif  // defined(OS_CHROMEOS)
 
 bool AreTouchEventsEnabled() {
+  static bool touch_status = ComputeTouchStatus();
+
 #if defined(OS_CHROMEOS)
-  return touch_events_enabled;
+  return touch_events_enabled && touch_status;
 #else
-  static bool touch_events_enabled = ComputeTouchStatus();
-  return touch_events_enabled;
+  return touch_status;
 #endif  // !defined(OS_CHROMEOS)
 }