Support navigating browsing contexts in the devtools.

Break the association between pipelines and browsing context actors.
Now there is one browsing context actor per actual browsing context,
and individual actors keep track of known pipelines as necessary.
There is also one console/performance/timeline/inspector/etc. actor
per browsing context.

This also centralizes more information in the browsing context actor.
Rather than duplicating state for the active pipeline in actors that
need to use it, each actor now remembers the name of its associated
browsing context actor and obtains that state whenever it's necessary.

components/devtools/actors/console.rs

@@ -8,6 +8,7 @@
 //! inspection, JS evaluation, autocompletion) in Servo.
 
 use crate::actor::{Actor, ActorMessageStatus, ActorRegistry};
+use crate::actors::browsing_context::BrowsingContextActor;
 use crate::actors::object::ObjectActor;
 use crate::protocol::JsonPacketStream;
 use crate::{ConsoleAPICall, ConsoleMessage, ConsoleMsg, PageErrorMsg};
@@ -17,10 +18,11 @@ use devtools_traits::EvaluateJSReply::{NullValue, NumberValue, VoidValue};
 use devtools_traits::{
     CachedConsoleMessageTypes, ConsoleAPI, DevtoolScriptControlMsg, LogLevel, PageError,
 };
-use ipc_channel::ipc::{self, IpcSender};
+use ipc_channel::ipc;
 use msg::constellation_msg::PipelineId;
 use serde_json::{self, Map, Number, Value};
 use std::cell::RefCell;
+use std::collections::HashMap;
 use std::net::TcpStream;
 use time::precise_time_ns;
 use uuid::Uuid;
@@ -106,10 +108,8 @@ struct SetPreferencesReply {
 
 pub struct ConsoleActor {
     pub name: String,
-    pub pipeline: PipelineId,
-    pub script_chan: IpcSender<DevtoolScriptControlMsg>,
-    pub streams: RefCell<Vec<TcpStream>>,
-    pub cached_events: RefCell<Vec<CachedConsoleMessage>>,
+    pub browsing_context: String,
+    pub cached_events: RefCell<HashMap<PipelineId, Vec<CachedConsoleMessage>>>,
 }
 
 impl ConsoleActor {
@@ -118,11 +118,13 @@ impl ConsoleActor {
         registry: &ActorRegistry,
         msg: &Map<String, Value>,
     ) -> Result<EvaluateJSReply, ()> {
+        let browsing_context = registry.find::<BrowsingContextActor>(&self.browsing_context);
         let input = msg.get("text").unwrap().as_str().unwrap().to_owned();
         let (chan, port) = ipc::channel().unwrap();
-        self.script_chan
+        browsing_context
+            .script_chan
             .send(DevtoolScriptControlMsg::EvaluateJS(
-                self.pipeline,
+                browsing_context.active_pipeline.get(),
                 input.clone(),
                 chan,
             ))
@@ -191,21 +193,35 @@ impl ConsoleActor {
         std::result::Result::Ok(reply)
     }
 
-    pub(crate) fn handle_page_error(&self, page_error: PageError) {
+    pub(crate) fn handle_page_error(
+        &self,
+        page_error: PageError,
+        pipeline: PipelineId,
+        browsing_context: &BrowsingContextActor,
+    ) {
         self.cached_events
             .borrow_mut()
+            .entry(pipeline)
+            .or_insert(vec![])
             .push(CachedConsoleMessage::PageError(page_error.clone()));
-        let msg = PageErrorMsg {
-            from: self.name(),
-            type_: "pageError".to_owned(),
-            pageError: page_error,
-        };
-        for stream in &mut *self.streams.borrow_mut() {
-            stream.write_json_packet(&msg);
+        if browsing_context.active_pipeline.get() == pipeline {
+            let msg = PageErrorMsg {
+                from: self.name(),
+                type_: "pageError".to_owned(),
+                pageError: page_error,
+            };
+            for stream in &mut *browsing_context.streams.borrow_mut() {
+                stream.write_json_packet(&msg);
+            }
         }
     }
 
-    pub(crate) fn handle_console_api(&self, console_message: ConsoleMessage) {
+    pub(crate) fn handle_console_api(
+        &self,
+        console_message: ConsoleMessage,
+        pipeline: PipelineId,
+        browsing_context: &BrowsingContextActor,
+    ) {
         let level = match console_message.logLevel {
             LogLevel::Debug => "debug",
             LogLevel::Info => "info",
@@ -216,6 +232,8 @@ impl ConsoleActor {
         .to_owned();
         self.cached_events
             .borrow_mut()
+            .entry(pipeline)
+            .or_insert(vec![])
             .push(CachedConsoleMessage::ConsoleAPI(ConsoleAPI {
                 type_: "ConsoleAPI".to_owned(),
                 level: level.clone(),
@@ -226,20 +244,22 @@ impl ConsoleActor {
                 private: false,
                 arguments: vec![console_message.message.clone()],
             }));
-        let msg = ConsoleAPICall {
-            from: self.name(),
-            type_: "consoleAPICall".to_owned(),
-            message: ConsoleMsg {
-                level: level,
-                timeStamp: precise_time_ns(),
-                arguments: vec![console_message.message],
-                filename: console_message.filename,
-                lineNumber: console_message.lineNumber,
-                columnNumber: console_message.columnNumber,
-            },
-        };
-        for stream in &mut *self.streams.borrow_mut() {
-            stream.write_json_packet(&msg);
+        if browsing_context.active_pipeline.get() == pipeline {
+            let msg = ConsoleAPICall {
+                from: self.name(),
+                type_: "consoleAPICall".to_owned(),
+                message: ConsoleMsg {
+                    level: level,
+                    timeStamp: precise_time_ns(),
+                    arguments: vec![console_message.message],
+                    filename: console_message.filename,
+                    lineNumber: console_message.lineNumber,
+                    columnNumber: console_message.columnNumber,
+                },
+            };
+            for stream in &mut *browsing_context.streams.borrow_mut() {
+                stream.write_json_packet(&msg);
+            }
         }
     }
 }
@@ -275,8 +295,16 @@ impl Actor for ConsoleActor {
                         s => debug!("unrecognized message type requested: \"{}\"", s),
                     };
                 }
+                let browsing_context =
+                    registry.find::<BrowsingContextActor>(&self.browsing_context);
                 let mut messages = vec![];
-                for event in self.cached_events.borrow().iter() {
+                for event in self
+                    .cached_events
+                    .borrow()
+                    .get(&browsing_context.active_pipeline.get())
+                    .unwrap_or(&vec![])
+                    .iter()
+                {
                     let include = match event {
                         CachedConsoleMessage::PageError(_)
                             if message_types.contains(CachedConsoleMessageTypes::PAGE_ERROR) =>