failed test: devtools/client/debugger/test/mochitest/browser_dbg-browser-content-toolbox.js
failed test: devtools/client/debugger/test/mochitest/browser_dbg-chrome-debugging.js
failed test: devtools/client/debugger/test/mochitest/browser_dbg-windowless-workers-early-breakpoint.js

diff --git a/devtools/server/actors/targets/browsing-context.js b/devtools/server/actors/targets/browsing-context.js
index 5e71b1320a5e..d2a7dac2d85c 100644
--- a/devtools/server/actors/targets/browsing-context.js
+++ b/devtools/server/actors/targets/browsing-context.js
@@ -1341,16 +1341,6 @@ const browsingContextTargetPrototype = {
       return;
     }
 
-    // Proceed normally only if the debuggee is not paused.
-    // TODO bug 997119: move that code to ThreadActor by listening to
-    // will-navigate
-    const threadActor = this.threadActor;
-    if (threadActor.state == "paused") {
-      threadActor.unsafeSynchronize(Promise.resolve(threadActor.doResume()));
-      threadActor.dbg.enabled = false;
-    }
-    threadActor.disableAllBreakpoints();
-
     this.emit("tabNavigated", {
       url: newURI,
       nativeConsoleAPI: true,
diff --git a/devtools/server/actors/thread.js b/devtools/server/actors/thread.js
index 182bf6d46736..cfb93b7693d5 100644
--- a/devtools/server/actors/thread.js
+++ b/devtools/server/actors/thread.js
@@ -99,6 +99,7 @@ const ThreadActor = ActorClassWithSpec(threadSpec, {
     this.objectGrip = this.objectGrip.bind(this);
     this.pauseObjectGrip = this.pauseObjectGrip.bind(this);
     this._onOpeningRequest = this._onOpeningRequest.bind(this);
+    this.onWillNavigate = this.onWillNavigate.bind(this)
 
     if (Services.obs) {
       // Set a wrappedJSObject property so |this| can be sent via the observer svc
@@ -279,6 +280,8 @@ const ThreadActor = ActorClassWithSpec(threadSpec, {
     this.sources.setOptions(this._options);
     this.sources.on("newSource", this.onNewSourceEvent);
 
+    this._parent.on("will-navigate", this.onWillNavigate);
+
     // Initialize an event loop stack. This can't be done in the constructor,
     // because this.conn is not yet initialized by the actor pool at that time.
     this._nestedEventLoops = new EventLoopStack({
@@ -348,19 +351,29 @@ const ThreadActor = ActorClassWithSpec(threadSpec, {
       return this._pauseOverlay;
     }

 
+  onWillNavigate: function () {
+    if (this.state == "paused") {
+      this.unsafeSynchronize(Promise.resolve(this.doResume()));
+      // this.doResume();
+      this.dbg.enabled = false;
+    }
+    this.disableAllBreakpoints();
+  },

https://hg.mozilla.org/mozilla-central/rev/f285ee7fedd7

Retroactively moving fixed bugs whose summaries mention "Fission" (or other Fission-related keywords) but are not assigned to a Fission Milestone to an appropriate Fission Milestone.

This will generate a lot of bugmail, so you can filter your bugmail for the following UUID and delete them en masse:

0ee3c76a-bc79-4eb2-8d12-05dc0b68e732