Fixes bug where Env/RootWindow would cache the wrong button

ui/base/x/events_x.cc

 // Copyright (c) 2012 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/events.h"
 
 #include <string.h>
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xlib.h>
@@ skipping 845 matching lines @@
   if (native_event->type == GenericEvent) {
     XIDeviceEvent* xievent =
         static_cast<XIDeviceEvent*>(native_event->xcookie.data);
     return xievent->evtype == XI_ButtonPress ||
            xievent->evtype == XI_ButtonRelease ||
            xievent->evtype == XI_Motion;
   }
   return false;
 }
 
+int GetChangedMouseButtonFlagsFromNative(
+    const base::NativeEvent& native_event) {
+  switch (native_event->type) {
+    case ButtonPress:
+    case ButtonRelease:
+      return GetEventFlagsFromXState(native_event->xbutton.state);
+    case GenericEvent: {
+      XIDeviceEvent* xievent =
+          static_cast<XIDeviceEvent*>(native_event->xcookie.data);
+      switch (xievent->evtype) {
+        case XI_ButtonPress:
+        case XI_ButtonRelease:
+          return GetEventFlagsForButton(EventButtonFromNative(native_event));
+        default:
+          break;
+      }
+    }
+    default:
+      break;
+  }
+  return 0;
+}
+
 int GetMouseWheelOffset(const base::NativeEvent& native_event) {
   int button = native_event->type == GenericEvent
     ? EventButtonFromNative(native_event) : native_event->xbutton.button;
 
   switch (button) {
     case 4:
       return kWheelScrollAmount;
     case 5:
       return -kWheelScrollAmount;
     default:
@@ skipping 112 matching lines @@
     noop->xclient.format = 8;
     DCHECK(!noop->xclient.display);
   }
   // Make sure we use atom from current xdisplay, which may
   // change during the test.
   noop->xclient.message_type = GetNoopEventAtom();
   return noop;
 }
 
 }  // namespace ui