Rewrite release event only if press event was rewritten for a given device.

chrome/browser/ui/ash/event_rewriter.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 "chrome/browser/ui/ash/event_rewriter.h"
 
 #include <vector>
 
 #include "ash/shell.h"
 #include "base/logging.h"
@@ skipping 985 matching lines @@
     return;
 
   // First, remap modifier masks.
   int remapped_flags = 0;
   unsigned int remapped_native_modifiers = 0U;
   GetRemappedModifierMasks(event->flags(), xievent->mods.effective,
                            &remapped_flags, &remapped_native_modifiers);
   xievent->mods.effective = remapped_native_modifiers;
 
   // Then, remap Alt+Button1 to Button3.
-  if ((xievent->mods.effective & Mod1Mask) && xievent->detail == 1) {
+  if ((xievent->evtype == XI_ButtonPress ||
+       pressed_device_ids_.count(xievent->sourceid)) &&
+      (xievent->mods.effective & Mod1Mask) && xievent->detail == Button1) {
     xievent->mods.effective &= ~Mod1Mask;
-    xievent->detail = 3;
+    xievent->detail = Button3;
     if (xievent->evtype == XI_ButtonRelease) {
       // On the release clear the left button from the existing state and the
       // mods, and set the right button.
-      XISetMask(xievent->buttons.mask, 3);
-      XIClearMask(xievent->buttons.mask, 1);
+      XISetMask(xievent->buttons.mask, Button3);
+      XIClearMask(xievent->buttons.mask, Button1);
       xievent->mods.effective &= ~Button1Mask;
+      pressed_device_ids_.erase(xievent->sourceid);
+    } else {
+      pressed_device_ids_.insert(xievent->sourceid);
     }
   }
 
   const int mouse_event_flags = event->flags() &
       (ui::EF_IS_DOUBLE_CLICK | ui::EF_IS_TRIPLE_CLICK | ui::EF_IS_NON_CLIENT |
        ui::EF_IS_SYNTHESIZED | ui::EF_FROM_TOUCH);
   event->set_flags(mouse_event_flags | ui::EventFlagsFromNative(xevent));
 #else
   // TODO(yusukes): Support Ash on other platforms if needed.
 #endif
@@ skipping 25 matching lines @@
   const DeviceType type = EventRewriter::GetDeviceType(device_name);
   if (type == kDeviceAppleKeyboard) {
     VLOG(1) << "Apple keyboard '" << device_name << "' connected: "
             << "id=" << device_id;
   }
   // Always overwrite the existing device_id since the X server may reuse a
   // device id for an unattached device.
   device_id_to_type_[device_id] = type;
   return type;
 }