Fix grabbing capture when the mouse is pressed on Desktop Linux.

ui/events/devices/x11/device_data_manager_x11.cc

 // Copyright 2014 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/events/devices/x11/device_data_manager_x11.h"
 
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xlib.h>
 
@@ skipping 184 matching lines @@
   return true;
 }
 
 bool DeviceDataManagerX11::IsXInput2Available() const {
   return xi_opcode_ != -1;
 }
 
 void DeviceDataManagerX11::UpdateDeviceList(Display* display) {
   cmt_devices_.reset();
   touchpads_.reset();
+  master_pointers_.clear();
   for (int i = 0; i < kMaxDeviceNum; ++i) {
     valuator_count_[i] = 0;
     valuator_lookup_[i].clear();
     data_type_lookup_[i].clear();
     valuator_min_[i].clear();
     valuator_max_[i].clear();
     for (int j = 0; j < kMaxSlotNum; j++)
       last_seen_valuator_[i][j].clear();
   }
 
@@ skipping 11 matching lines @@
   // Update the structs with new valuator information
   XIDeviceList info_list =
       ui::DeviceListCacheX11::GetInstance()->GetXI2DeviceList(display);
   Atom atoms[DT_LAST_ENTRY];
   for (int data_type = 0; data_type < DT_LAST_ENTRY; ++data_type)
     atoms[data_type] = atom_cache_.GetAtom(kCachedAtoms[data_type]);
 
   for (int i = 0; i < info_list.count; ++i) {
     XIDeviceInfo* info = info_list.devices + i;
 
+    if (info->use == XIMasterPointer)
+      master_pointers_.push_back(info->deviceid);
+
     // We currently handle only slave, non-keyboard devices
     if (info->use != XISlavePointer && info->use != XIFloatingSlave)
       continue;
 
     bool possible_cmt = false;
     bool not_cmt = false;
     const int deviceid = info->deviceid;
 
     for (int j = 0; j < info->num_classes; ++j) {
       if (info->classes[j]->type == XIValuatorClass)
@@ skipping 503 matching lines @@
     } else {
       keyboards.erase(it);
       ++blocked_iter;
     }
   }
   // Notify base class of updated list.
   DeviceDataManager::OnKeyboardDevicesUpdated(keyboards);
 }
 
 }  // namespace ui