Fire visibilityChange event on out-of-process iframes.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 75ee58153b242cc359ea2d4a2a72834d5109f920..a4c2a23706116da370919061991d3a9a1a739a12 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -898,9 +898,6 @@ RenderFrameImpl* RenderFrameImpl::CreateMainFrame(
   render_view->webview()->setMainFrame(web_frame);
   render_frame->render_widget_ = RenderWidget::CreateForFrame(
       widget_routing_id, hidden, screen_info, compositor_deps, web_frame);
-  // TODO(kenrb): Observing shouldn't be necessary when we sort out
-  // WasShown and WasHidden, separating page-level visibility from
-  // frame-level visibility.
   // TODO(avi): This DCHECK is to track cleanup for https://crbug.com/545684
   DCHECK_EQ(render_view->GetWidget(), render_frame->render_widget_)
       << "Main frame is no longer reusing the RenderView as its widget! "
@@ -977,12 +974,8 @@ void RenderFrameImpl::CreateFrame(
     // TODO(avi): The main frame re-uses the RenderViewImpl as its widget, so
     // avoid double-registering the frame as an observer.
     // https://crbug.com/545684
-    if (web_frame->parent()) {
-      // TODO(kenrb): Observing shouldn't be necessary when we sort out
-      // WasShown and WasHidden, separating page-level visibility from
-      // frame-level visibility.
+    if (web_frame->parent())
       render_frame->render_widget_->RegisterRenderFrame(render_frame);
-    }
   }
 
   render_frame->Initialize();
@@ -1632,7 +1625,6 @@ void RenderFrameImpl::OnSwapOut(
 
   // Let WebKit know that this view is hidden so it can drop resources and
   // stop compositing.
-  // TODO(creis): Support this for subframes as well.

[Charlie Reis, 2016/06/08 21:39:07]

Hopefully this happens via another path (e.g., a WasHidden IPC) if the last
local subframe gets swapped out but there are still proxies keeping the
RenderView around?

[lfg, 2016/06/08 21:53:50]

There's actually nothing that would handle this. How can we keep the RenderView
(and therefore the WebView) alive if all the local subframes are gone?

The downside is that in the meantime we'll be using a bit more resources than
needed, but we should clean everything up when the WebView/WebWidget split is
completed.

[Charlie Reis, 2016/06/08 22:18:35]

This happens if you have proxies due to a reference from another tab.  For
example, a LocalFrame in one window could have a tree of RemoteFrames in its
opener window.
It'd be nice to solve it soon, but I'm not too concerned about it.  That said,
maybe we should leave a more detailed TODO here instead of removing it.

[lfg, 2016/06/08 22:47:34]

I see. I think the correct way to do this, is to destroy the WebWidget on swap,
which I believe we already do for subframes (and we should do the same for the
main frame once we split WebView/WebWidget).

Actually, now that I think about this, I think this code should be removed. This
is not the ideal scenario, and we are wasting some resources for now, but
setting the visibility to Hidden in the webview has unwanted consequences, for
instance, the WebViewScheduler will set every local frame to Hidden, regardless
if it's the same local root or not, which is wrong.

The only thing I'm a bit worried here is how much we are wasting in terms of
resources by setting the RenderWidgetCompositor to visible, even though we'll
never draw to this widget.

   if (is_main_frame_) {
     render_view_->webview()->setVisibilityState(
         blink::WebPageVisibilityStateHidden, false);
@@ -3905,7 +3897,7 @@ void RenderFrameImpl::willSendRequest(
   int parent_routing_id = parent ? GetRoutingIdForFrameOrProxy(parent) : -1;
 
   RequestExtraData* extra_data = new RequestExtraData();
-  extra_data->set_visibility_state(render_view_->visibilityState());
+  extra_data->set_visibility_state(visibilityState());
   extra_data->set_custom_user_agent(custom_user_agent);
   extra_data->set_requested_with(requested_with);
   extra_data->set_render_frame_id(routing_id_);
@@ -4379,27 +4371,25 @@ void RenderFrameImpl::WasHidden() {
   for (auto* plugin : active_pepper_instances_)
     plugin->PageVisibilityChanged(false);
 #endif  // ENABLE_PLUGINS
+
+  if (GetWebFrame()->frameWidget()) {
+    static_cast<blink::WebFrameWidget*>(GetWebFrame()->frameWidget())
+        ->setVisibilityState(visibilityState());
+  }
 }
 
 void RenderFrameImpl::WasShown() {
-  // TODO(kenrb): Need to figure out how to do this better. Should
-  // VisibilityState remain a page-level concept or move to frames?
-  // The semantics of 'Show' might have to change here.
-  // TODO(avi): This DCHECK is to track cleanup for https://crbug.com/545684
-  DCHECK(!IsMainFrame() || render_widget_.get() == render_view_.get())
-      << "The main render frame is no longer reusing the RenderView as its "
-      << "RenderWidget!";
-  if (render_widget_ && render_widget_->webwidget() &&
-      render_view_.get() != render_widget_.get()) {
-    static_cast<blink::WebFrameWidget*>(render_widget_->webwidget())->
-        setVisibilityState(blink::WebPageVisibilityStateVisible, false);
-  }
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, WasShown());
 
 #if defined(ENABLE_PLUGINS)
   for (auto* plugin : active_pepper_instances_)
     plugin->PageVisibilityChanged(true);
 #endif  // ENABLE_PLUGINS
+
+  if (GetWebFrame()->frameWidget()) {
+    static_cast<blink::WebFrameWidget*>(GetWebFrame()->frameWidget())
+        ->setVisibilityState(visibilityState());
+  }
 }
 
 void RenderFrameImpl::WidgetWillClose() {
@@ -6023,6 +6013,24 @@ blink::ServiceRegistry* RenderFrameImpl::serviceRegistry() {
   return &blink_service_registry_;
 }
 
+blink::WebPageVisibilityState RenderFrameImpl::visibilityState() const {
+  RenderFrameImpl* local_root =
+      RenderFrameImpl::FromWebFrame(frame_->localRoot());
+  blink::WebPageVisibilityState current_state =
+      local_root->render_widget_->is_hidden()
+          ? blink::WebPageVisibilityStateHidden
+          : blink::WebPageVisibilityStateVisible;
+  blink::WebPageVisibilityState override_state = current_state;
+  if (GetContentClient()->renderer()->ShouldOverridePageVisibilityState(
+          this, &override_state))
+    return override_state;
+  return current_state;
+}
+
+blink::WebPageVisibilityState RenderFrameImpl::GetVisibilityState() const {
+  return visibilityState();
+}
+
 blink::WebPlugin* RenderFrameImpl::GetWebPluginForFind() {
   if (frame_->document().isPluginDocument())
     return frame_->document().to<WebPluginDocument>().plugin();