Bug 1520835 - Removed now-useless front pool from DebuggerClient. r=jdescottes

Depends on D20704

Differential Revision: https://phabricator.services.mozilla.com/D20705

--HG--
extra : moz-landing-system : lando

devtools/shared/client/debugger-client.js

@@ -22,7 +22,6 @@ loader.lazyRequireGetter(this, "EventEmitter", "devtools/shared/event-emitter");
 loader.lazyRequireGetter(this, "RootFront", "devtools/shared/fronts/root", true);
 loader.lazyRequireGetter(this, "ThreadClient", "devtools/shared/client/thread-client");
 loader.lazyRequireGetter(this, "ObjectClient", "devtools/shared/client/object-client");
-loader.lazyRequireGetter(this, "Pool", "devtools/shared/protocol", true);
 loader.lazyRequireGetter(this, "Front", "devtools/shared/protocol", true);
 
 /**
@@ -38,16 +37,6 @@ function DebuggerClient(transport) {
   // To be removed once all clients are refactored to protocol.js
   this._clients = new Map();
 
-  // Pool of fronts instanciated by this class.
-  // This is useful for actors that have already been transitioned to protocol.js
-  // Once RootClient becomes a protocol.js actor, these actors can be attached to it
-  // instead of this pool.
-  // This Pool will automatically be added to this._pools via addActorPool once the first
-  // Front will be added to it (in attachTarget, ...).
-  // And it does not need to destroyed explicitly as all Pools are destroyed on client
-  // closing.
-  this._frontPool = new Pool(this);
-
   this._pendingRequests = new Map();
   this._activeRequests = new Map();
   this._eventsEnabled = true;
@@ -64,7 +53,11 @@ function DebuggerClient(transport) {
   this.mainRoot = null;
   this.expectReply("root", (packet) => {
     this.mainRoot = new RootFront(this, packet);
-    this._frontPool.manage(this.mainRoot);
+
+    // Root Front is a special case, managing itself as it doesn't have any parent.
+    // It will register itself to DebuggerClient as a Pool via Front._poolMap.
+    this.mainRoot.manage(this.mainRoot);
+
     this.emit("connected", packet.applicationType, packet.traits);
   });
 }