Hide/show widget on Windows screen lock/unlock

ui/views/controls/native/native_view_host.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/controls/native/native_view_host.h"
 
 #include "base/logging.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/gfx/canvas.h"
 #include "ui/views/accessibility/native_view_accessibility.h"
@@ skipping 109 matching lines @@
   // It would be nice if this used some approximation of the page's
   // current background color.
   if (native_wrapper_->HasInstalledClip())
     canvas->FillRect(GetLocalBounds(), resize_background_color_);
 }
 
 void NativeViewHost::VisibilityChanged(View* starting_from, bool is_visible) {
   Layout();
 }
 
+void NativeViewHost::OnSoftVisibilityChanged(bool visible) {
+  if (!native_view_ || !native_wrapper_.get())
+    return;
+
+  if (GetVisibleBounds().IsEmpty())
+    return;
+
+  // If the widget wasn't .e.g. minimized, hide and show would trigger
+  // PageVisibility API, enabling JS to save power while screen is locked.
+  if (visible) {
+    Layout();
+  } else {
+    native_wrapper_->HideWidget();
+  }
+}
+
 bool NativeViewHost::GetNeedsNotificationWhenVisibleBoundsChange() const {
   // The native widget is placed relative to the root. As such, we need to
   // know when the position of any ancestor changes, or our visibility relative
   // to other views changed as it'll effect our position relative to the root.
   return true;
 }
 
 void NativeViewHost::OnVisibleBoundsChanged() {
   Layout();
 }
@@ skipping 70 matching lines @@
   Widget::Widgets widgets;
   Widget::GetAllChildWidgets(native_view(), &widgets);
   for (Widget::Widgets::iterator i = widgets.begin(); i != widgets.end(); ++i) {
     focus_manager->ViewRemoved((*i)->GetRootView());
     if (!focus_manager->GetFocusedView())
       return;
   }
 }
 
 }  // namespace views