Reducing CPU cycles of hidden/minimized browser windows

content/browser/web_contents/web_contents_view_aura.cc

Index: content/browser/web_contents/web_contents_view_aura.cc
diff --git a/content/browser/web_contents/web_contents_view_aura.cc b/content/browser/web_contents/web_contents_view_aura.cc
index f134da3b24a005846f9d5709db22112628a86698..a7d5116d0a4eb7e0cd776456eaeb3c61544f4c76 100644
--- a/content/browser/web_contents/web_contents_view_aura.cc
+++ b/content/browser/web_contents/web_contents_view_aura.cc
@@ -98,6 +98,28 @@ bool ShouldNavigateBack(const NavigationController& controller,
          controller.CanGoBack();
 }
 
+// Check if a given |child_window| is below a given |window| in the hierarchy.
+bool IsInHierarchyBelow(aura::Window* child_window, aura::Window* window) {
+  aura::Window* childs_parent = child_window->parent();
+  if (!childs_parent)
+    return false;
+  if (childs_parent == window)
+    return true;
+  return IsInHierarchyBelow(childs_parent, window);
+}
+
+// Update the |visibility| of the |web contents|.
+void UpdateWebContentsVisibility(WebContentsImpl* web_contents,
+                                 bool visibility) {
+  if (visibility) {
+    if (!web_contents->should_normally_be_visible())
+      web_contents->WasShown();
+  } else {
+    if (web_contents->should_normally_be_visible())
+      web_contents->WasHidden();
+  }
+}
+
 RenderWidgetHostViewAura* ToRenderWidgetHostViewAura(
     RenderWidgetHostView* view) {
   if (!view || RenderViewHostFactory::has_factory())
@@ -721,6 +743,7 @@ WebContentsViewAura::~WebContentsViewAura() {
 
   // Window needs a valid delegate during its destructor, so we explicitly
   // delete it here.
+  window_->RemoveObserver(this);
   window_.reset();
 }
 
@@ -1045,6 +1068,7 @@ void WebContentsViewAura::CreateView(
   window_->SetType(ui::wm::WINDOW_TYPE_CONTROL);
   window_->SetTransparent(false);
   window_->Init(aura::WINDOW_LAYER_NOT_DRAWN);
+  window_->AddObserver(this);
   aura::Window* root_window = context ? context->GetRootWindow() : NULL;
   if (root_window) {
     // There are places where there is no context currently because object
@@ -1429,10 +1453,6 @@ void WebContentsViewAura::OnWindowDestroyed(aura::Window* window) {
 }
 
 void WebContentsViewAura::OnWindowTargetVisibilityChanged(bool visible) {
-  if (visible)
-    web_contents_->WasShown();
-  else
-    web_contents_->WasHidden();
 }
 
 bool WebContentsViewAura::HasHitTestMask() const {
@@ -1555,4 +1575,18 @@ int WebContentsViewAura::OnPerformDrop(const ui::DropTargetEvent& event) {
   return ConvertFromWeb(current_drag_op_);
 }
 
+void WebContentsViewAura::OnWindowParentChanged(aura::Window* window,
+                                                aura::Window* parent) {
+  UpdateWebContentsVisibility(web_contents_, !parent || parent->IsVisible());
+}
+
+void WebContentsViewAura::OnWindowVisibilityChanged(aura::Window* window,
+                                                    bool visible) {
+  // Ignore any visibility changes in the hierarchy below.
+  if (IsInHierarchyBelow(window, window_.get()))

[sky, 2014/05/20 19:46:27]

Isn't this the same as window_->Contains(window) && window_ != window ?

[Mr4D (OOO till 08-26), 2014/05/20 21:26:56]

Done.

+    return;
+
+  UpdateWebContentsVisibility(web_contents_, visible);
+}
+
 }  // namespace content