Avoids releasing capture in EndMoveLoop if capture was switched to another window while dragging

ui/views/widget/desktop_aura/x11_whole_screen_move_loop.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/views/widget/desktop_aura/x11_whole_screen_move_loop.h"
 
 #include <X11/Xlib.h>
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
 #undef RootWindow
 
@@ skipping 44 matching lines @@
 
 }  // namespace
 
 X11WholeScreenMoveLoop::X11WholeScreenMoveLoop(
     X11WholeScreenMoveLoopDelegate* delegate)
     : delegate_(delegate),
       in_move_loop_(false),
       should_reset_mouse_flags_(false),
       grab_input_window_(None),
       canceled_(false),
+      has_grab_(false),
       weak_factory_(this) {
   last_xmotion_.type = LASTEvent;
 }
 
 X11WholeScreenMoveLoop::~X11WholeScreenMoveLoop() {}
 
 void X11WholeScreenMoveLoop::DispatchMouseMovement() {
   if (!weak_factory_.HasWeakPtrs())
     return;
   weak_factory_.InvalidateWeakPtrs();
@@ skipping 54 matching lines @@
       return ui::POST_DISPATCH_NONE;
     }
     case KeyPress: {
       if (ui::KeyboardCodeFromXKeyEvent(xev) == ui::VKEY_ESCAPE) {
         canceled_ = true;
         EndMoveLoop();
         return ui::POST_DISPATCH_NONE;
       }
       break;
     }
+    case FocusOut: {
+      if (xev->xfocus.mode != NotifyGrab)
+        has_grab_ = false;
+      break;
+    }
     case GenericEvent: {
       ui::EventType type = ui::EventTypeFromNative(xev);
       switch (type) {
         case ui::ET_MOUSE_MOVED:
         case ui::ET_MOUSE_DRAGGED:
         case ui::ET_MOUSE_RELEASED: {
           XEvent xevent = {0};
           if (type == ui::ET_MOUSE_RELEASED) {
             xevent.type = ButtonRelease;
             xevent.xbutton.button = ui::EventButtonFromNative(xev);
@@ skipping 97 matching lines @@
     aura::Env::GetInstance()->set_mouse_button_flags(0);
     should_reset_mouse_flags_ = false;
   }
 
   // TODO(erg): Is this ungrab the cause of having to click to give input focus
   // on drawn out windows? Not ungrabbing here screws the X server until I kill
   // the chrome process.
 
   // Ungrab before we let go of the window.
   XDisplay* display = gfx::GetXDisplay();
-  XUngrabPointer(display, CurrentTime);
-  XUngrabKeyboard(display, CurrentTime);
+  // Only ungrab pointer if capture was not switched to another window.
+  if (has_grab_) {
+    XUngrabPointer(display, CurrentTime);
+    XUngrabKeyboard(display, CurrentTime);
+  }
 
   // Restore the previous dispatcher.
   nested_dispatcher_.reset();
   drag_widget_.reset();
   delegate_->OnMoveLoopEnded();
   XDestroyWindow(display, grab_input_window_);
   grab_input_window_ = None;
 
   in_move_loop_ = false;
   quit_closure_.Run();
@@ skipping 20 matching lines @@
       ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
       GrabModeAsync,
       GrabModeAsync,
       None,
       cursor.platform(),
       CurrentTime);
   if (ret != GrabSuccess) {
     DLOG(ERROR) << "Grabbing pointer for dragging failed: "
                 << ui::GetX11ErrorString(display, ret);
   } else {
+    has_grab_ = true;
     XUngrabKeyboard(display, CurrentTime);
     ret = XGrabKeyboard(
         display,
         grab_input_window_,
         False,
         GrabModeAsync,
         GrabModeAsync,
         CurrentTime);
     if (ret != GrabSuccess) {
       DLOG(ERROR) << "Grabbing keyboard for dragging failed: "
@@ skipping 66 matching lines @@
     for (int x = 0; x < in_bitmap->width(); ++x) {
       if (SkColorGetA(in_row[x]) > kMinAlpha)
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace views