Auto merge of #8612 - glennw:pending-frames, r=jdm

Add test to constellation to avoid writing reftest image if there are pending frames.

This changes several tests that contain <iframe></iframe> from FAIL to TIMEOUT. This is correct
since there is a bug that prevents these iframes from ever rendering.

~~~There are also a few previous FAILs that changed to OK. These may be intermittents or they
may genuinely be fixed by this change.~~~

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8612)
<!-- Reviewable:end -->

1 files changed, 5 insertions, 1 deletions

diff --git a/components/script_traits/script_msg.rs b/components/script_traits/script_msg.rs
index 7769dbe8597..b19212dc2d1 100644
--- a/components/script_traits/script_msg.rs
+++ b/components/script_traits/script_msg.rs
@@ -6,7 +6,7 @@ use canvas_traits::CanvasMsg;
 use euclid::point::Point2D;
 use euclid::size::Size2D;
 use ipc_channel::ipc::IpcSender;
-use msg::constellation_msg::{AnimationState, IframeLoadInfo, NavigationDirection};
+use msg::constellation_msg::{AnimationState, DocumentState, IframeLoadInfo, NavigationDirection};
 use msg::constellation_msg::{Failure, MozBrowserEvent, PipelineId};
 use msg::constellation_msg::{LoadData, SubpageId};
 use msg::constellation_msg::{MouseButton, MouseEventType};
@@ -66,4 +66,8 @@ pub enum ScriptMsg {
     SetCursor(Cursor),
     /// Notifies the constellation that the viewport has been constrained in some manner
     ViewportConstrained(PipelineId, ViewportConstraints),
+    /// Mark a new document as active
+    ActivateDocument(PipelineId),
+    /// Set the document state for a pipeline (used by screenshot / reftests)
+    SetDocumentState(PipelineId, DocumentState),
 }