Bug 915372 - Clean up inspector front and actor when reusing connection. r=paul

browser/devtools/framework/target.js

@@ -428,6 +428,10 @@ TabTarget.prototype = {
     // Before taking any action, notify listeners that destruction is imminent.
     this.emit("close");
 
+    if (this._inspector) {
+      this._inspector.destroy();
+    }
+
     // First of all, do cleanup tasks that pertain to both remoted and
     // non-remoted targets.
     this.off("thread-resumed", this._handleThreadState);

browser/devtools/framework/toolbox.js

@@ -940,14 +940,18 @@ Toolbox.prototype = {
 
     this._telemetry.destroy();
 
-    // Targets need to be notified that the toolbox is being torn down.
-    if (this._target) {
-      this._target.off("close", this.destroy);
-      outstanding.push(this._target.destroy());
-    }
-    this._target = null;
-
-    promise.all(outstanding).then(function() {
+    promise.all(outstanding).then(() => {
+      // Targets need to be notified that the toolbox is being torn down.
+      // This is done after other destruction tasks since it may tear down
+      // fronts and the debugger transport which earlier destroy methods may
+      // require to complete.
+      if (this._target) {
+        let target = this._target;
+        this._target = null;
+        target.off("close", this.destroy);
+        return target.destroy();
+      }
+    }).then(function() {
       this.emit("destroyed");
       // Free _host after the call to destroyed in order to let a chance
       // to destroyed listeners to still query toolbox attributes

toolkit/devtools/server/actors/inspector.js

@@ -817,6 +817,7 @@ var WalkerActor = protocol.ActorClass({
     this._activePseudoClassLocks = null;
     this.progressListener.destroy();
     this.rootDoc = null;
+    events.emit(this, "destroyed");
     protocol.Actor.prototype.destroy.call(this);
   },
 
@@ -2208,6 +2209,10 @@ var InspectorActor = protocol.ActorClass({
       let tabActor = this.tabActor;
       window.removeEventListener("DOMContentLoaded", domReady, true);
       this.walker = WalkerActor(this.conn, tabActor, options);
+      events.once(this.walker, "destroyed", () => {
+        this._walkerPromise = null;
+        this._pageStylePromise = null;
+      });
       deferred.resolve(this.walker);
     };
 

toolkit/devtools/server/protocol.js

@@ -1047,7 +1047,10 @@ let Front = Class({
 
     // Remaining packets must be responses.
     if (this._requests.length === 0) {
-      throw Error("Unexpected packet from " + this.actorID + ", " + packet.type);
+      let msg = "Unexpected packet from " + this.actorID + ", " + packet.type;
+      let err = Error(msg);
+      console.error(err);
+      throw err;
     }
 
     let deferred = this._requests.shift();