Make browser windows override_redirect when dragging tabs.

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.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/desktop_window_tree_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 286 matching lines @@
   window()->SetProperty(kViewsWindowForRootWindow, content_window_);
   window()->SetProperty(kHostForRootWindow, this);
 
   // Ensure that the X11DesktopHandler exists so that it dispatches activation
   // messages to us.
   X11DesktopHandler::get();
 
   // TODO(erg): Unify this code once the other consumer goes away.
   SwapNonClientEventHandler(
       scoped_ptr<ui::EventHandler>(new X11WindowEventFilter(this)).Pass());
-  SetUseNativeFrame(params.type == Widget::InitParams::TYPE_WINDOW &&
+  SetUseNativeFrame((params.type == Widget::InitParams::TYPE_WINDOW ||
+                     params.type == Widget::InitParams::TYPE_DRAG_BROWSER) &&
                     !params.remove_standard_frame);
 
   x11_window_move_client_.reset(new X11DesktopWindowMoveClient);
   aura::client::SetWindowMoveClient(window(), x11_window_move_client_.get());
 
   SetWindowTransparency();
 
   native_widget_delegate_->OnNativeWidgetCreated(true);
 }
 
@@ skipping 774 matching lines @@
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_TOOLTIP");
       break;
     case Widget::InitParams::TYPE_POPUP:
       swa.override_redirect = True;
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_NOTIFICATION");
       break;
     case Widget::InitParams::TYPE_DRAG:
       swa.override_redirect = True;
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_DND");
       break;
+    case Widget::InitParams::TYPE_DRAG_BROWSER:
+      swa.override_redirect = True;
+      break;
     default:
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_NORMAL");
       break;
   }
   if (swa.override_redirect)
     attribute_mask |= CWOverrideRedirect;
 
   // Detect whether we're running inside a compositing manager. If so, try to
   // use the ARGB visual. Otherwise, just use our parent's visual.
   Visual* visual = CopyFromParent;
@@ skipping 160 matching lines @@
       ViewsDelegate::GetInstance()
           ? ViewsDelegate::GetInstance()->GetDefaultWindowIcon()
           : NULL;
   if (window_icon) {
     SetWindowIcons(gfx::ImageSkia(), *window_icon);
   }
   CreateCompositor();
   OnAcceleratedWidgetAvailable();
 }
 
+void DesktopWindowTreeHostX11::RemapWindow() {
+  XUnmapWindow(xdisplay_, xwindow_);
+  XSetWindowAttributes swa;
+  swa.override_redirect = False;

[Daniel Erat, 2015/12/28 21:33:02]

i wouldn't have expected a method named RemapWindow() to additionally change the
window's override-redirect attribute. maybe rename it to RemapAsNormalWindow()?

[stapelberg, 2016/01/18 17:22:23]

Done.

+  XChangeWindowAttributes(xdisplay_, xwindow_, CWOverrideRedirect, &swa);
+  XMapWindow(xdisplay_, xwindow_);
+}
+
 gfx::Size DesktopWindowTreeHostX11::AdjustSize(
     const gfx::Size& requested_size_in_pixels) {
   std::vector<gfx::Display> displays =
       gfx::Screen::GetScreenByType(gfx::SCREEN_TYPE_NATIVE)->GetAllDisplays();
   // Compare against all monitor sizes. The window manager can move the window
   // to whichever monitor it wants.
   for (size_t i = 0; i < displays.size(); ++i) {
     if (requested_size_in_pixels == displays[i].GetSizeInPixel()) {
       return gfx::Size(requested_size_in_pixels.width() - 1,
                        requested_size_in_pixels.height() - 1);
@@ skipping 764 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views