Reducing CPU cycles of hidden/minimized browser windows

ui/views/controls/native/native_view_host_aura.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_aura.h"
 
 #include "base/logging.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 #include "ui/base/cursor/cursor.h"
@@ skipping 94 matching lines @@
   if (host_->native_view())
     return host_->native_view()->GetCursor(gfx::Point(x, y));
   return gfx::kNullCursor;
 }
 
 void NativeViewHostAura::OnWindowDestroyed(aura::Window* window) {
   DCHECK(window == host_->native_view());
   host_->NativeViewDestroyed();
 }
 
+void NativeViewHostAura::OnWindowVisibilityChanged(aura::Window* window,

[sky, 2014/05/15 22:42:19]

Again, I think this should be done at the content layer. If
WebContents/RenderWidget want to do something special when an ancestor is hidden
then it should install the necessary listeners to do that.

+                                                   bool is_visible) {
+  // To reduce background activity of minimized / non visible browser content,
+  // we let the native view follow its parent's visibility which will suppress
+  // further renderer updates.
+  // Note: In case of browser navigations, the window visibility will change to
+  // invisible as well and cause long "flashes". By following the parent's
+  // windows visibility, we only suppress rendering in case of minimizing /
+  // general invisibility.
+  if (host_->native_view() &&
+      host_->native_view()->parent() &&
+      is_visible == host_->native_view()->parent()->IsVisible()) {
+    if (is_visible)
+      host_->native_view()->Show();
+    else
+      host_->native_view()->Hide();
+  }
+}
+
 // static
 NativeViewHostWrapper* NativeViewHostWrapper::CreateWrapper(
     NativeViewHost* host) {
   return new NativeViewHostAura(host);
 }
 
 }  // namespace views