Plumb native AppWindow input region through to window shape under Aura.

ui/views/widget/desktop_aura/desktop_root_window_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_root_window_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 412 matching lines @@
   if (!XGetGeometry(xdisplay_, x_root_window_, &root, &x, &y,
                     &width, &height, &border_width, &depth)) {
     NOTIMPLEMENTED();
     return gfx::Rect(0, 0, 10, 10);
   }
 
   return gfx::Rect(x, y, width, height);
 }
 
 void DesktopRootWindowHostX11::SetShape(gfx::NativeRegion native_region) {
-  SkPath path;
-  native_region->getBoundaryPath(&path);
-  Region region = gfx::CreateRegionFromSkPath(path);
-  XShapeCombineRegion(xdisplay_, xwindow_, ShapeBounding, 0, 0, region, false);
-  XDestroyRegion(region);
+  if (native_region) {
+    SkPath path;
+    native_region->getBoundaryPath(&path);
+    Region region = gfx::CreateRegionFromSkPath(path);
+    XShapeCombineRegion(
+        xdisplay_, xwindow_, ShapeBounding, 0, 0, region, false);
+    XDestroyRegion(region);
+  } else {
+    ResetWindowRegion();
+  }
+
+  delete native_region;
 }
 
 void DesktopRootWindowHostX11::Activate() {
   X11DesktopHandler::get()->ActivateWindow(xwindow_);
 }
 
 void DesktopRootWindowHostX11::Deactivate() {
   // Deactivating a window means activating nothing.
   X11DesktopHandler::get()->ActivateWindow(None);
 }
@@ skipping 969 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme();
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views