Auto merge of #17425 - paulrouget:attach-pipeline-2, r=asajeffrey

cleanup embedder/compositor/constellation/script messages

Fix: #17226 #17200 #17201

This is work in progress. Some tests still fail.
I'd like to get early feedback as it's a pretty large PR.

There is nothing fundamentally new. Basically, I added TopLevelBrowsingContrextId to the relevant messages between the embedder, the compositor and the constellation, and enforced the PipelineId to be attached to each ScriptMsg (see #17201).

I unaliased all the ScriptMsg. It was getting difficult to understand the nature of the message as ScriptMsg was used aliased CompositorMsg sometimes (CompositorMsg is an actually type of message already). I renamed constellation_chan to script_to_constellation_chan, again, for clarification.

This cleanup code is necessary for #15934 and for tabs support.

/cc @asajeffrey can I ask you to look at this? No need for a formal review, I need feedback at this stage.

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1 files changed, 3 insertions, 4 deletions

diff --git a/components/script/dom/htmltextareaelement.rs b/components/script/dom/htmltextareaelement.rs
index 3033480b03d..fc48564d030 100755
--- a/components/script/dom/htmltextareaelement.rs
+++ b/components/script/dom/htmltextareaelement.rs
@@ -27,8 +27,7 @@ use dom::validation::Validatable;
 use dom::virtualmethods::VirtualMethods;
 use dom_struct::dom_struct;
 use html5ever::{LocalName, Prefix};
-use ipc_channel::ipc::IpcSender;
-use script_traits::ScriptMsg as ConstellationMsg;
+use script_traits::ScriptToConstellationChan;
 use std::cell::Cell;
 use std::default::Default;
 use std::ops::Range;
@@ -40,7 +39,7 @@ use textinput::{KeyReaction, Lines, SelectionDirection, TextInput};
 pub struct HTMLTextAreaElement {
     htmlelement: HTMLElement,
     #[ignore_heap_size_of = "#7193"]
-    textinput: DOMRefCell<TextInput<IpcSender<ConstellationMsg>>>,
+    textinput: DOMRefCell<TextInput<ScriptToConstellationChan>>,
     placeholder: DOMRefCell<DOMString>,
     // https://html.spec.whatwg.org/multipage/#concept-textarea-dirty
     value_changed: Cell<bool>,
@@ -109,7 +108,7 @@ impl HTMLTextAreaElement {
     fn new_inherited(local_name: LocalName,
                      prefix: Option<Prefix>,
                      document: &Document) -> HTMLTextAreaElement {
-        let chan = document.window().upcast::<GlobalScope>().constellation_chan().clone();
+        let chan = document.window().upcast::<GlobalScope>().script_to_constellation_chan().clone();
         HTMLTextAreaElement {
             htmlelement:
                 HTMLElement::new_inherited_with_state(IN_ENABLED_STATE | IN_READ_WRITE_STATE,