User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0 Build ID: 20160414030247 Steps to reproduce: 1. Start Nightly or Aurora 2. Open the Browser Content Toolbox (menubar > Tools > Web Developer > Browser Content Toolbox) 3. Click Memory tab Actual results: - Memory tool is blank - Title bar does not update when selecting Memory tab Expected results: Memory tool and title bar works correctly.

Thanks for the bug report! Did you happen to see any error messages in the browser console?

(In reply to Nick Fitzgerald [:fitzgen] [⏰PDT; UTC-7] from comment #1) > Thanks for the bug report! Did you happen to see any error messages in the > browser console? 03:54:36.964 Error: Can't manage front without an actor ID. Ensure server supports memory. Stack trace: Front<.manage@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/protocol.js:1133:13 exports.MemoryFront<.initialize@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/memory.js:192:5 constructor@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/core/heritage.js:146:23 MemoryPanel.prototype.open<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/memory/panel.js:31:28 TaskImpl_run@resource://gre/modules/Task.jsm:319:40 promise callback*TaskImpl_handleResultValue@resource://gre/modules/Task.jsm:395:7 TaskImpl_run@resource://gre/modules/Task.jsm:327:13 TaskImpl@resource://gre/modules/Task.jsm:280:3 createAsyncFunction/asyncFunction@resource://gre/modules/Task.jsm:254:14 Toolbox.prototype.loadTool/onLoad@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/framework/toolbox.js:1310:19 1Promise-backend.js:940

The memory tool appears if we have the trait heapSnapshots[1], but that does not mean the actors are actually accessible everywhere. We should change this to use hasActor or similar (can keep the trait check too if you want). If you want to add the memory tool support, we should add the actors it needs to the ChildProcessActor[2]. [1]: https://dxr.mozilla.org/mozilla-central/rev/21bf1af375c1fa8565ae3bb2e89bd1a0809363d4/devtools/client/definitions.js#294 [2]: https://dxr.mozilla.org/mozilla-central/rev/21bf1af375c1fa8565ae3bb2e89bd1a0809363d4/devtools/server/actors/child-process.js#82-94

Comment on attachment 8993340 [details] Bug 1264873 - Ensure exposing memory actor for the browser content toolbox. https://reviewboard.mozilla.org/r/258124/#review265446 this looks good to me

Pushed by apoirot@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/18f56efc4093 Ensure exposing memory actor for the browser content toolbox. r=yulia