--- a/browser/installer/allowed-dupes.mn
+++ b/browser/installer/allowed-dupes.mn
@@ -24,28 +24,26 @@ browser/chrome/browser/skin/classic/brow
 browser/chrome/browser/skin/classic/browser/controlcenter/warning-gray.svg
 # devtools reduction is bug 1311178
 browser/chrome/devtools/content/dom/content/dom-view.css
 browser/chrome/devtools/content/dom/dom.html
 browser/chrome/devtools/content/dom/main.js
 browser/chrome/devtools/content/framework/toolbox-options.js
 browser/chrome/devtools/content/inspector/fonts/fonts.js
 browser/chrome/devtools/content/inspector/inspector.xhtml
-browser/chrome/devtools/content/memory/initializer.js
 browser/chrome/devtools/content/projecteditor/lib/helpers/readdir.js
 browser/chrome/devtools/content/shared/theme-switching.js
 browser/chrome/devtools/modules/devtools/client/dom/content/dom-view.css
 browser/chrome/devtools/modules/devtools/client/dom/dom.html
 browser/chrome/devtools/modules/devtools/client/dom/main.js
 browser/chrome/devtools/modules/devtools/client/framework/toolbox-options.js
 browser/chrome/devtools/modules/devtools/client/inspector/fonts/fonts.js
 browser/chrome/devtools/modules/devtools/client/inspector/inspector.xhtml
 browser/chrome/devtools/modules/devtools/client/jsonview/css/controls.png
 browser/chrome/devtools/modules/devtools/client/jsonview/css/controls@2x.png
-browser/chrome/devtools/modules/devtools/client/memory/initializer.js
 browser/chrome/devtools/modules/devtools/client/projecteditor/lib/helpers/readdir.js
 browser/chrome/devtools/modules/devtools/client/shared/theme-switching.js
 browser/chrome/devtools/modules/devtools/client/themes/common.css
 browser/chrome/devtools/modules/devtools/client/themes/toolbars.css
 browser/chrome/devtools/modules/devtools/client/themes/variables.css
 browser/chrome/devtools/skin/common.css
 browser/chrome/devtools/skin/toolbars.css
 browser/chrome/devtools/skin/images/command-scratchpad.svg

--- a/devtools/client/jar.mn
+++ b/devtools/client/jar.mn
@@ -71,17 +71,16 @@ devtools.jar:
     content/performance/views/details-abstract-subview.js (performance/views/details-abstract-subview.js)
     content/performance/views/details-waterfall.js (performance/views/details-waterfall.js)
     content/performance/views/details-js-call-tree.js (performance/views/details-js-call-tree.js)
     content/performance/views/details-js-flamegraph.js (performance/views/details-js-flamegraph.js)
     content/performance/views/details-memory-call-tree.js (performance/views/details-memory-call-tree.js)
     content/performance/views/details-memory-flamegraph.js (performance/views/details-memory-flamegraph.js)
     content/performance/views/recordings.js (performance/views/recordings.js)
     content/memory/memory.xhtml (memory/memory.xhtml)
-    content/memory/initializer.js (memory/initializer.js)
     content/commandline/commandlineoutput.xhtml (commandline/commandlineoutput.xhtml)
     content/commandline/commandlinetooltip.xhtml (commandline/commandlinetooltip.xhtml)
     content/framework/toolbox-window.xul (framework/toolbox-window.xul)
     content/framework/toolbox-options.xhtml (framework/toolbox-options.xhtml)
 *   content/framework/toolbox.xul (framework/toolbox.xul)
     content/framework/toolbox-init.js (framework/toolbox-init.js)
     content/framework/options-panel.css (framework/options-panel.css)
     content/framework/toolbox-process-window.xul (framework/toolbox-process-window.xul)

--- a/devtools/client/memory/initializer.js
+++ b/devtools/client/memory/initializer.js
@@ -1,70 +1,69 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* exported initialize, destroy, Promise */
 
 "use strict";
 
-const BrowserLoaderModule = {};
-ChromeUtils.import("resource://devtools/client/shared/browser-loader.js", BrowserLoaderModule);
-const { require } = BrowserLoaderModule.BrowserLoader({
-  baseURI: "resource://devtools/client/memory/",
-  window
-});
 const { createFactory, createElement } = require("devtools/client/shared/vendor/react");
 const ReactDOM = require("devtools/client/shared/vendor/react-dom");
 const { Provider } = require("devtools/client/shared/vendor/react-redux");
 const App = createFactory(require("devtools/client/memory/app"));
 const Store = require("devtools/client/memory/store");
 const { assert } = require("devtools/shared/DevToolsUtils");
-const Promise = require("Promise");
+
+// Shared variables used by several methods of this module.
+let root, store, unsubscribe;
 
-/**
- * The current target, toolbox, MemoryFront, and HeapAnalysesClient,
- * set by this tool's host.
- */
-var gToolbox, gFront, gHeapAnalysesClient;
+const initialize = async function() {
+  // Exposed by panel.js
+  let { gFront, gToolbox, gHeapAnalysesClient } = window;
 
-/**
- * Variables set by `initialize()`
- */
-var gStore, gRoot, gApp, gProvider, unsubscribe, isHighlighted;
+  root = document.querySelector("#app");
+  store = Store();
+  const app = createElement(App, {
+    toolbox: gToolbox,
+    front: gFront,
+    heapWorker: gHeapAnalysesClient
+  });
+  const provider = createElement(Provider, { store }, app);
+  ReactDOM.render(provider, root);
+  unsubscribe = store.subscribe(onStateChange);
 
-var initialize = async function() {
-  gRoot = document.querySelector("#app");
-  gStore = Store();
-  gApp = createElement(App,
-    { toolbox: gToolbox, front: gFront, heapWorker: gHeapAnalysesClient });
-  gProvider = createElement(Provider, { store: gStore }, gApp);
-  ReactDOM.render(gProvider, gRoot);
-  unsubscribe = gStore.subscribe(onStateChange);
+  // Exposed for tests.
+  window.gStore = store;
 };
 
-var destroy = async function() {
-  const ok = ReactDOM.unmountComponentAtNode(gRoot);
+const destroy = async function() {
+  const ok = ReactDOM.unmountComponentAtNode(root);
   assert(ok, "Should successfully unmount the memory tool's top level React component");
 
   unsubscribe();
+};
 
-  gStore = gRoot = gApp = gProvider = unsubscribe = isHighlighted = null;
-};
+// Current state
+let isHighlighted;
 
 /**
  * Fired on any state change, currently only handles toggling
  * the highlighting of the tool when recording allocations.
  */
 function onStateChange() {
-  let isRecording = gStore.getState().allocations.recording;
+  let { gToolbox } = window;
+
+  let isRecording = store.getState().allocations.recording;
   if (isRecording === isHighlighted) {
     return;
   }
 
   if (isRecording) {
     gToolbox.highlightTool("memory");
   } else {
     gToolbox.unhighlightTool("memory");
   }
 
   isHighlighted = isRecording;
 }
+
+module.exports = { initialize, destroy };

--- a/devtools/client/memory/memory.xhtml
+++ b/devtools/client/memory/memory.xhtml
@@ -20,21 +20,16 @@
     <div id="app"></div>
 
     <script type="application/javascript"
             src="chrome://devtools/content/shared/theme-switching.js"
             defer="true">
     </script>
 
     <script type="application/javascript"
-            src="initializer.js"
-            defer="true">
-    </script>
-
-    <script type="application/javascript"
             src="chrome://devtools/content/shared/vendor/d3.js"
             defer="true">
     </script>
 
     <script type="application/javascript"
             src="chrome://devtools/content/shared/vendor/dagre-d3.js"
             defer="true">
     </script>

--- a/devtools/client/memory/moz.build
+++ b/devtools/client/memory/moz.build
@@ -11,16 +11,17 @@ DIRS += [
     'components',
     'reducers',
 ]
 
 DevToolsModules(
     'app.js',
     'constants.js',
     'dominator-tree-lazy-children.js',
+    'initializer.js',
     'models.js',
     'panel.js',
     'reducers.js',
     'store.js',
     'utils.js',
 )
 
 BROWSER_CHROME_MANIFESTS += ['test/browser/browser.ini']

--- a/devtools/client/memory/panel.js
+++ b/devtools/client/memory/panel.js
@@ -1,22 +1,30 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const EventEmitter = require("devtools/shared/event-emitter");
 const { MemoryFront } = require("devtools/shared/fronts/memory");
+const { Cu } = require("chrome");
 const HeapAnalysesClient = require("devtools/shared/heapsnapshot/HeapAnalysesClient");
 
 function MemoryPanel(iframeWindow, toolbox) {
   this.panelWin = iframeWindow;
   this._toolbox = toolbox;
 
+  const { BrowserLoader } = Cu.import("resource://devtools/client/shared/browser-loader.js", {});
+  const browserRequire = BrowserLoader({
+    baseURI: "resource://devtools/client/memory/",
+    window: this.panelWin
+  }).require;
+  this.initializer = browserRequire("devtools/client/memory/initializer");
+
   EventEmitter.decorate(this);
 }
 
 MemoryPanel.prototype = {
   async open() {
     if (this._opening) {
       return this._opening;
     }
@@ -27,17 +35,17 @@ MemoryPanel.prototype = {
     const rootForm = await this.target.root;
     this.panelWin.gFront = new MemoryFront(this.target.client,
                                            this.target.form,
                                            rootForm);
     this.panelWin.gHeapAnalysesClient = new HeapAnalysesClient();
 
     await this.panelWin.gFront.attach();
 
-    this._opening = this.panelWin.initialize().then(() => {
+    this._opening = this.initializer.initialize().then(() => {
       this.isReady = true;
       this.emit("ready");
       return this;
     });
 
     return this._opening;
   },
 
@@ -50,17 +58,17 @@ MemoryPanel.prototype = {
   async destroy() {
     // Make sure this panel is not already destroyed.
     if (this._destroyer) {
       return this._destroyer;
     }
 
     await this.panelWin.gFront.detach();
 
-    this._destroyer = this.panelWin.destroy().then(() => {
+    this._destroyer = this.initializer.destroy().then(() => {
       // Destroy front to ensure packet handler is removed from client
       this.panelWin.gFront.destroy();
       this.panelWin.gHeapAnalysesClient.destroy();
       this.panelWin = null;
       this._opening = null;
       this.isReady = false;
       this.emit("destroyed");
     });