Register iframes with the devtools (#35874)

Previously, the devtools didn't know about
<iframe>s. They either ignored messages coming from
iframes or crashed.

This reverts https://github.com/servo/servo/pull/34032
and then filters out non-tab globals in the "listTabs"
message to the root actor.

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

components/devtools/actors/browsing_context.rs

@@ -180,7 +180,11 @@ impl BrowsingContextActor {
         actors: &mut ActorRegistry,
     ) -> BrowsingContextActor {
         let name = actors.new_name("target");
-        let DevtoolsPageInfo { title, url } = page_info;
+        let DevtoolsPageInfo {
+            title,
+            url,
+            is_top_level_global,
+        } = page_info;
 
         let accessibility = AccessibilityActor::new(actors.new_name("accessibility"));
 
@@ -205,7 +209,7 @@ impl BrowsingContextActor {
 
         let style_sheets = StyleSheetsActor::new(actors.new_name("stylesheets"));
 
-        let tabdesc = TabDescriptorActor::new(actors, name.clone());
+        let tabdesc = TabDescriptorActor::new(actors, name.clone(), is_top_level_global);
 
         let thread = ThreadActor::new(actors.new_name("thread"));
 

components/devtools/actors/root.rs

@@ -200,10 +200,14 @@ impl Actor for RootActor {
                     tabs: self
                         .tabs
                         .iter()
-                        .map(|target| {
-                            registry
-                                .find::<TabDescriptorActor>(target)
-                                .encodable(registry, false)
+                        .filter_map(|target| {
+                            let tab_actor = registry.find::<TabDescriptorActor>(target);
+                            // Filter out iframes and workers
+                            if tab_actor.is_top_level_global() {
+                                Some(tab_actor.encodable(registry, false))
+                            } else {
+                                None
+                            }
                         })
                         .collect(),
                 };

components/devtools/actors/tab.rs

@@ -65,6 +65,7 @@ struct GetWatcherReply {
 pub struct TabDescriptorActor {
     name: String,
     browsing_context_actor: String,
+    is_top_level_global: bool,
 }
 
 impl Actor for TabDescriptorActor {
@@ -125,6 +126,7 @@ impl TabDescriptorActor {
     pub(crate) fn new(
         actors: &mut ActorRegistry,
         browsing_context_actor: String,
+        is_top_level_global: bool,
     ) -> TabDescriptorActor {
         let name = actors.new_name("tab-description");
         let root = actors.find_mut::<RootActor>("root");
@@ -132,6 +134,7 @@ impl TabDescriptorActor {
         TabDescriptorActor {
             name,
             browsing_context_actor,
+            is_top_level_global,
         }
     }
 
@@ -157,4 +160,8 @@ impl TabDescriptorActor {
             url,
         }
     }
+
+    pub(crate) fn is_top_level_global(&self) -> bool {
+        self.is_top_level_global
+    }
 }