Bug 1556489 - P19. Fix devtools stack traces. r=honza,ochameau

DevTools rely on events when a new HttpChannel is opened, it needs to know when a DocumentChannel is.

Differential Revision: https://phabricator.services.mozilla.com/D40975

devtools/server/actors/network-monitor/stack-trace-collector.js

@@ -35,6 +35,7 @@ function StackTraceCollector(filters, netmonitors) {
 StackTraceCollector.prototype = {
   init() {
     Services.obs.addObserver(this, "http-on-opening-request");
+    Services.obs.addObserver(this, "document-on-opening-request");
     Services.obs.addObserver(this, "network-monitor-alternate-stack");
     ChannelEventSinkFactory.getService().registerCollector(this);
     this.onGetStack = this.onGetStack.bind(this);
@@ -48,6 +49,7 @@ StackTraceCollector.prototype = {
 
   destroy() {
     Services.obs.removeObserver(this, "http-on-opening-request");
+    Services.obs.removeObserver(this, "document-on-opening-request");
     Services.obs.removeObserver(this, "network-monitor-alternate-stack");
     ChannelEventSinkFactory.getService().unregisterCollector(this);
     for (const { messageManager } of this.netmonitors) {
@@ -77,22 +79,30 @@ StackTraceCollector.prototype = {
   observe(subject, topic, data) {
     let channel, id;
     try {
-      channel = subject.QueryInterface(Ci.nsIIdentChannel);
+      // We need to QI nsIHttpChannel in order to load the interface's
+      // methods / attributes for later code that could assume we are dealing
+      // with a nsIHttpChannel.
+      channel = subject.QueryInterface(Ci.nsIHttpChannel);
       id = channel.channelId;
     } catch (e1) {
-      // WebSocketChannels do not have IDs, so use the URL. When a WebSocket is
-      // opened in a content process, a channel is created locally but the HTTP
-      // channel for the connection lives entirely in the parent process. When
-      // the server code running in the parent sees that HTTP channel, it will
-      // look for the creation stack using the websocket's URL.
       try {
-        channel = subject.QueryInterface(Ci.nsIWebSocketChannel);
+        channel = subject.QueryInterface(Ci.nsIIdentChannel);
+        id = channel.channelId;
       } catch (e2) {
-        // Channels which don't implement the above interfaces can appear here,
-        // such as nsIFileChannel. Ignore these channels.
-        return;
+        // WebSocketChannels do not have IDs, so use the URL. When a WebSocket is
+        // opened in a content process, a channel is created locally but the HTTP
+        // channel for the connection lives entirely in the parent process. When
+        // the server code running in the parent sees that HTTP channel, it will
+        // look for the creation stack using the websocket's URL.
+        try {
+          channel = subject.QueryInterface(Ci.nsIWebSocketChannel);
+        } catch (e3) {
+          // Channels which don't implement the above interfaces can appear here,
+          // such as nsIFileChannel. Ignore these channels.
+          return;
+        }
+        id = channel.URI.spec;
       }
-      id = channel.URI.spec;
     }
 
     if (!matchRequest(channel, this.filters)) {
@@ -101,7 +111,8 @@ StackTraceCollector.prototype = {
 
     const stacktrace = [];
     switch (topic) {
-      case "http-on-opening-request": {
+      case "http-on-opening-request":
+      case "document-on-opening-request": {
         // The channel is being opened on the main thread, associate the current
         // stack with it.
         //

netwerk/ipc/DocumentChannelChild.cpp

@@ -113,6 +113,8 @@ DocumentChannelChild::AsyncOpen(nsIStreamListener* aListener) {
      return mStatus;
   }
 
+  gHttpHandler->OnOpeningDocumentRequest(this);
+
   DocumentChannelCreationArgs args;
 
   SerializeURI(topWindowURI, args.topWindowURI());

netwerk/protocol/http/nsHttpHandler.h

@@ -361,6 +361,10 @@ class nsHttpHandler final : public nsIHttpProtocolHandler,
     NotifyObservers(chan, NS_HTTP_ON_OPENING_REQUEST_TOPIC);
   }
 
+  void OnOpeningDocumentRequest(nsIIdentChannel* chan) {
+    NotifyObservers(chan, NS_DOCUMENT_ON_OPENING_REQUEST_TOPIC);
+  }
+
   // Called by the channel before writing a request
   void OnModifyRequest(nsIHttpChannel* chan) {
     NotifyObservers(chan, NS_HTTP_ON_MODIFY_REQUEST_TOPIC);

netwerk/protocol/http/nsIHttpProtocolHandler.idl

@@ -120,6 +120,12 @@ interface nsIHttpProtocolHandler : nsIProxiedProtocolHandler
  */
 #define NS_HTTP_ON_OPENING_REQUEST_TOPIC "http-on-opening-request"
 
+ /**
+ * This observer topic is notified when an document channel is opened.
+ * It is similar to http-on-opening-request.
+ */
+#define NS_DOCUMENT_ON_OPENING_REQUEST_TOPIC "document-on-opening-request"
+
 /**
  * Before an HTTP request is sent to the server, this observer topic is
  * notified.  The observer of this topic can then choose to set any additional