Expose the visibility state of a frame to the browser process.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index 4093fa9f698f325c21289150288f9486a3475abc..7f4f1891467ace3af2642b72f3bef6efe6ae64e7 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -1477,6 +1477,15 @@ bool RenderFrameHostImpl::IsFocused() const {
          frame_tree_->GetFocusedFrame()->current_frame_host() == this;
 }
 
+blink::WebPageVisibilityState RenderFrameHostImpl::GetVisibilityState() {
+  if (GetContentClient()->browser()->IsPrerendering(this))
+    return blink::WebPageVisibilityStatePrerender;
+
+  return GetRenderWidgetHost()->is_hidden()
+            ? blink::WebPageVisibilityStateHidden

[Charlie Reis, 2015/01/22 21:03:55]

This indent doesn't seem right.  I would have done 4 spaces past "return", but
I've also seen 4 spaces past "GetRenderWidgetHost()" from clang-format.  This is
3 spaces past.

[mlamouri (slow - plz ping), 2015/01/23 12:32:57]

Fixed.

+            : blink::WebPageVisibilityStateVisible;
+}
+
 void RenderFrameHostImpl::UpdateCrossProcessIframeAccessibility(
     const std::map<int32, int>& node_to_frame_routing_id_map) {
   for (const auto& iter : node_to_frame_routing_id_map) {