diff --git a/browser/devtools/commandline/BuiltinCommands.jsm b/browser/devtools/commandline/BuiltinCommands.jsm
index 7638c3fdda5..0aaf7619b76 100644
--- a/browser/devtools/commandline/BuiltinCommands.jsm
+++ b/browser/devtools/commandline/BuiltinCommands.jsm
@@ -1747,7 +1747,8 @@ XPCOMUtils.defineLazyModuleGetter(this, "AppCacheUtils",
           width = window.innerWidth;
           height = window.innerHeight;
         } else {
-          let rect = LayoutHelpers.getRect(node, window);
+          let lh = new LayoutHelpers(window);
+          let rect = lh.getRect(node, window);
           top = rect.top;
           left = rect.left;
           width = rect.width;
diff --git a/browser/devtools/debugger/debugger-controller.js b/browser/devtools/debugger/debugger-controller.js
index 734f4efebcc..6d0067eb3ee 100644
--- a/browser/devtools/debugger/debugger-controller.js
+++ b/browser/devtools/debugger/debugger-controller.js
@@ -19,7 +19,6 @@ Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/devtools/dbg-client.jsm");
 let promise = Cu.import("resource://gre/modules/commonjs/sdk/core/promise.js").Promise;
 Cu.import("resource:///modules/source-editor.jsm");
-Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm");
 Cu.import("resource:///modules/devtools/BreadcrumbsWidget.jsm");
 Cu.import("resource:///modules/devtools/SideMenuWidget.jsm");
 Cu.import("resource:///modules/devtools/VariablesView.jsm");
@@ -40,6 +39,13 @@ Object.defineProperty(this, "NetworkHelper", {
   enumerable: true
 });
 
+Object.defineProperty(this, "DevtoolsHelpers", {
+  get: function() {
+    return devtools.require("devtools/shared/helpers");
+  },
+  configurable: true,
+  enumerable: true
+});
 
 /**
  * Object defining the debugger controller components.
diff --git a/browser/devtools/debugger/debugger-toolbar.js b/browser/devtools/debugger/debugger-toolbar.js
index 076c2cdab19..e08aa4bb5ad 100644
--- a/browser/devtools/debugger/debugger-toolbar.js
+++ b/browser/devtools/debugger/debugger-toolbar.js
@@ -38,10 +38,10 @@ ToolbarView.prototype = {
     this._stepOutButton = document.getElementById("step-out");
     this._chromeGlobals = document.getElementById("chrome-globals");
 
-    let resumeKey = LayoutHelpers.prettyKey(document.getElementById("resumeKey"), true);
-    let stepOverKey = LayoutHelpers.prettyKey(document.getElementById("stepOverKey"), true);
-    let stepInKey = LayoutHelpers.prettyKey(document.getElementById("stepInKey"), true);
-    let stepOutKey = LayoutHelpers.prettyKey(document.getElementById("stepOutKey"), true);
+    let resumeKey = DevtoolsHelpers.prettyKey(document.getElementById("resumeKey"), true);
+    let stepOverKey = DevtoolsHelpers.prettyKey(document.getElementById("stepOverKey"), true);
+    let stepInKey = DevtoolsHelpers.prettyKey(document.getElementById("stepInKey"), true);
+    let stepOutKey = DevtoolsHelpers.prettyKey(document.getElementById("stepOutKey"), true);
     this._resumeTooltip = L10N.getFormatStr("resumeButtonTooltip", resumeKey);
     this._pauseTooltip = L10N.getFormatStr("pauseButtonTooltip", resumeKey);
     this._stepOverTooltip = L10N.getFormatStr("stepOverTooltip", stepOverKey);
@@ -729,12 +729,12 @@ FilterView.prototype = {
     this._variableOperatorButton = document.getElementById("variable-operator-button");
     this._variableOperatorLabel = document.getElementById("variable-operator-label");
 
-    this._fileSearchKey = LayoutHelpers.prettyKey(document.getElementById("fileSearchKey"), true);
-    this._globalSearchKey = LayoutHelpers.prettyKey(document.getElementById("globalSearchKey"), true);
-    this._filteredFunctionsKey = LayoutHelpers.prettyKey(document.getElementById("functionSearchKey"), true);
-    this._tokenSearchKey = LayoutHelpers.prettyKey(document.getElementById("tokenSearchKey"), true);
-    this._lineSearchKey = LayoutHelpers.prettyKey(document.getElementById("lineSearchKey"), true);
-    this._variableSearchKey = LayoutHelpers.prettyKey(document.getElementById("variableSearchKey"), true);
+    this._fileSearchKey = DevtoolsHelpers.prettyKey(document.getElementById("fileSearchKey"), true);
+    this._globalSearchKey = DevtoolsHelpers.prettyKey(document.getElementById("globalSearchKey"), true);
+    this._filteredFunctionsKey = DevtoolsHelpers.prettyKey(document.getElementById("functionSearchKey"), true);
+    this._tokenSearchKey = DevtoolsHelpers.prettyKey(document.getElementById("tokenSearchKey"), true);
+    this._lineSearchKey = DevtoolsHelpers.prettyKey(document.getElementById("lineSearchKey"), true);
+    this._variableSearchKey = DevtoolsHelpers.prettyKey(document.getElementById("variableSearchKey"), true);
 
     this._searchbox.addEventListener("click", this._onClick, false);
     this._searchbox.addEventListener("select", this._onSearch, false);
diff --git a/browser/devtools/debugger/test/browser_dbg_pause-resume.js b/browser/devtools/debugger/test/browser_dbg_pause-resume.js
index 1f886cd17d2..537a39dcd42 100644
--- a/browser/devtools/debugger/test/browser_dbg_pause-resume.js
+++ b/browser/devtools/debugger/test/browser_dbg_pause-resume.js
@@ -8,7 +8,7 @@ var gPane = null;
 var gTab = null;
 var gDebugger = null;
 var gView = null;
-var gLH = null;
+var gDH = null;
 var gL10N = null;
 
 function test() {
@@ -17,7 +17,7 @@ function test() {
     gPane = aPane;
     gDebugger = gPane.panelWin;
     gView = gDebugger.DebuggerView;
-    gLH = gDebugger.LayoutHelpers;
+    gDH = gDebugger.DevtoolsHelpers;
     gL10N = gDebugger.L10N;
 
     testPause();
@@ -31,7 +31,7 @@ function testPause() {
   let button = gDebugger.document.getElementById("resume");
   is(button.getAttribute("tooltiptext"),
      gL10N.getFormatStr("pauseButtonTooltip",
-      gLH.prettyKey(gDebugger.document.getElementById("resumeKey"))),
+      gDH.prettyKey(gDebugger.document.getElementById("resumeKey"))),
     "Button tooltip should be pause when running.");
 
   gDebugger.DebuggerController.activeThread.addOneTimeListener("paused", function() {
@@ -45,7 +45,7 @@ function testPause() {
 
       is(button.getAttribute("tooltiptext"),
          gL10N.getFormatStr("resumeButtonTooltip",
-          gLH.prettyKey(gDebugger.document.getElementById("resumeKey"))),
+          gDH.prettyKey(gDebugger.document.getElementById("resumeKey"))),
         "Button tooltip should be resume when paused.");
 
       is(frames.querySelectorAll(".dbg-stackframe").length, 0,
@@ -70,7 +70,7 @@ function testResume() {
       let button = gDebugger.document.getElementById("resume");
       is(button.getAttribute("tooltiptext"),
          gL10N.getFormatStr("pauseButtonTooltip",
-          gLH.prettyKey(gDebugger.document.getElementById("resumeKey"))),
+          gDH.prettyKey(gDebugger.document.getElementById("resumeKey"))),
         "Button tooltip should be pause when running.");
 
       closeDebuggerAndFinish();
@@ -88,6 +88,6 @@ registerCleanupFunction(function() {
   gTab = null;
   gDebugger = null;
   gView = null;
-  gLH = null;
+  gDH = null;
   gL10N = null;
 });
diff --git a/browser/devtools/inspector/breadcrumbs.js b/browser/devtools/inspector/breadcrumbs.js
index 37c608f1b52..25910863027 100644
--- a/browser/devtools/inspector/breadcrumbs.js
+++ b/browser/devtools/inspector/breadcrumbs.js
@@ -11,7 +11,6 @@ const ENSURE_SELECTION_VISIBLE_DELAY = 50; // ms
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource:///modules/devtools/DOMHelpers.jsm");
-Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 
 let promise = require("sdk/core/promise");
diff --git a/browser/devtools/inspector/highlighter.js b/browser/devtools/inspector/highlighter.js
index 5d796b508b6..279c0ab63be 100644
--- a/browser/devtools/inspector/highlighter.js
+++ b/browser/devtools/inspector/highlighter.js
@@ -93,6 +93,7 @@ function LocalHighlighter(aTarget, aInspector, aToolbox)
   this.chromeDoc = this.tab.ownerDocument;
   this.chromeWin = this.chromeDoc.defaultView;
   this.inspector = aInspector
+  this.layoutHelpers = new LayoutHelpers(this.browser.contentWindow);
 
   EventEmitter.decorate(this);
 
@@ -225,7 +226,7 @@ LocalHighlighter.prototype = {
       this.invalidateSize();
       if (!this._highlighting &&
           this.selection.reason != "highlighter") {
-        LayoutHelpers.scrollIntoViewIfNeeded(this.selection.node);
+        this.layoutHelpers.scrollIntoViewIfNeeded(this.selection.node);
       }
     } else {
       this.disabled = true;
@@ -255,7 +256,7 @@ LocalHighlighter.prototype = {
     }
 
     let clientRect = this.selection.node.getBoundingClientRect();
-    let rect = LayoutHelpers.getDirtyRect(this.selection.node);
+    let rect = this.layoutHelpers.getDirtyRect(this.selection.node);
     this.highlightRectangle(rect);
 
     this.moveInfobar();
@@ -461,7 +462,7 @@ LocalHighlighter.prototype = {
     texthbox.addEventListener("mousedown", function(aEvent) {
       // On click, show the node:
       if (this.selection.isElementNode()) {
-        LayoutHelpers.scrollIntoViewIfNeeded(this.selection.node);
+        this.layoutHelpers.scrollIntoViewIfNeeded(this.selection.node);
       }
     }.bind(this), true);
 
@@ -514,7 +515,7 @@ LocalHighlighter.prototype = {
       return; // same rectangle
     }
 
-    let aRectScaled = LayoutHelpers.getZoomedRect(this.win, aRect);
+    let aRectScaled = this.layoutHelpers.getZoomedRect(this.win, aRect);
 
     if (aRectScaled.left >= 0 && aRectScaled.top >= 0 &&
         aRectScaled.width > 0 && aRectScaled.height > 0) {
@@ -809,7 +810,7 @@ LocalHighlighter.prototype = {
     // This should never happen, but just in case, we don't let the
     // highlighter highlight browser nodes.
     if (doc && doc != this.chromeDoc) {
-      let element = LayoutHelpers.getElementFromPoint(aEvent.target.ownerDocument,
+      let element = this.layoutHelpers.getElementFromPoint(aEvent.target.ownerDocument,
         aEvent.clientX, aEvent.clientY);
       if (element && element != this.selection.node) {
         this.selection.setNode(element, "highlighter");
diff --git a/browser/devtools/inspector/test/browser_inspector_bug_817558_delete_node.js b/browser/devtools/inspector/test/browser_inspector_bug_817558_delete_node.js
index 41076fe8c83..746df998f08 100644
--- a/browser/devtools/inspector/test/browser_inspector_bug_817558_delete_node.js
+++ b/browser/devtools/inspector/test/browser_inspector_bug_817558_delete_node.js
@@ -33,7 +33,8 @@ function test()
 
       let tmp = {};
       Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm", tmp);
-      ok(!tmp.LayoutHelpers.isNodeConnected(node), "Node considered as disconnected.");
+      let lh = new tmp.LayoutHelpers(window.content);
+      ok(!lh.isNodeConnected(node), "Node considered as disconnected.");
 
       // Wait for the inspector to process the mutation
       inspector.once("inspector-updated", () => {
diff --git a/browser/devtools/inspector/test/browser_inspector_destroyselection.js b/browser/devtools/inspector/test/browser_inspector_destroyselection.js
index ea75f4d4629..f0eaabe02d0 100644
--- a/browser/devtools/inspector/test/browser_inspector_destroyselection.js
+++ b/browser/devtools/inspector/test/browser_inspector_destroyselection.js
@@ -33,7 +33,8 @@ function test()
 
     let tmp = {};
     Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm", tmp);
-    ok(!tmp.LayoutHelpers.isNodeConnected(node), "Node considered as disconnected.");
+    let lh = new tmp.LayoutHelpers(window.content);
+    ok(!lh.isNodeConnected(node), "Node considered as disconnected.");
     ok(!inspector.selection.isConnected(), "Selection considered as disconnected");
 
     finishUp();
diff --git a/browser/devtools/inspector/test/head.js b/browser/devtools/inspector/test/head.js
index 5b7a5653505..aa0541b131f 100644
--- a/browser/devtools/inspector/test/head.js
+++ b/browser/devtools/inspector/test/head.js
@@ -77,7 +77,8 @@ function getHighlitNode()
   // Get midpoint of diagonal line.
   let midpoint = midPoint(a, b);
 
-  return LayoutHelpers.getElementFromPoint(h.win.document, midpoint.x,
+  let lh = new LayoutHelpers(window.content);
+  return lh.getElementFromPoint(h.win.document, midpoint.x,
     midpoint.y);
 }
 
diff --git a/browser/devtools/layoutview/view.js b/browser/devtools/layoutview/view.js
index 6f80d708d47..c2b86cd0ff8 100644
--- a/browser/devtools/layoutview/view.js
+++ b/browser/devtools/layoutview/view.js
@@ -8,7 +8,6 @@
 
 const Cu = Components.utils;
 Cu.import("resource://gre/modules/Services.jsm");
-Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm");
 Cu.import("resource://gre/modules/devtools/Loader.jsm");
 Cu.import("resource://gre/modules/devtools/Console.jsm");
 
diff --git a/browser/devtools/markupview/markup-view.js b/browser/devtools/markupview/markup-view.js
index 94f10c78aa1..3bc496072b9 100644
--- a/browser/devtools/markupview/markup-view.js
+++ b/browser/devtools/markupview/markup-view.js
@@ -53,6 +53,8 @@ function MarkupView(aInspector, aFrame, aControllerWindow)
   this.doc = this._frame.contentDocument;
   this._elt = this.doc.querySelector("#root");
 
+  this.layoutHelpers = new LayoutHelpers(this.doc.defaultView);
+
   try {
     this.maxChildren = Services.prefs.getIntPref("devtools.markup.pagesize");
   } catch(ex) {
@@ -406,7 +408,7 @@ MarkupView.prototype = {
       return this._ensureVisible(aNode);
     }).then(() => {
       // Why is this not working?
-      LayoutHelpers.scrollIntoViewIfNeeded(this._containers.get(aNode).editor.elt, centered);
+      this.layoutHelpers.scrollIntoViewIfNeeded(this._containers.get(aNode).editor.elt, centered);
     });
   },
 
@@ -1231,7 +1233,7 @@ ElementEditor.prototype = {
     // Double quotes need to be handled specially to prevent DOMParser failing.
     // name="v"a"l"u"e" when editing -> name='v"a"l"u"e"'
     // name="v'a"l'u"e" when editing -> name="v'a"l'u"e"
-    let editValueDisplayed = aAttr.value;
+    let editValueDisplayed = aAttr.value || "";
     let hasDoubleQuote = editValueDisplayed.contains('"');
     let hasSingleQuote = editValueDisplayed.contains("'");
     let initial = aAttr.name + '="' + editValueDisplayed + '"';
diff --git a/browser/devtools/scratchpad/scratchpad.js b/browser/devtools/scratchpad/scratchpad.js
index de3c2c821b6..76cf6d74c6c 100644
--- a/browser/devtools/scratchpad/scratchpad.js
+++ b/browser/devtools/scratchpad/scratchpad.js
@@ -19,6 +19,7 @@ let require = Components.utils.import("resource://gre/modules/devtools/Loader.js
 let { Cc, Ci, Cu } = require("chrome");
 let promise = require("sdk/core/promise");
 let Telemetry = require("devtools/shared/telemetry");
+let DevtoolsHelpers = require("devtools/shared/helpers");
 let TargetFactory = require("devtools/framework/target").TargetFactory;
 const escodegen = require("escodegen/escodegen");
 
@@ -26,7 +27,6 @@ Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/NetUtil.jsm");
 Cu.import("resource:///modules/source-editor.jsm");
-Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm");
 Cu.import("resource:///modules/devtools/scratchpad-manager.jsm");
 Cu.import("resource://gre/modules/jsdebugger.jsm");
 Cu.import("resource:///modules/devtools/gDevTools.jsm");
@@ -1284,9 +1284,9 @@ var Scratchpad = {
 
     let initialText = this.strings.formatStringFromName(
       "scratchpadIntro1",
-      [LayoutHelpers.prettyKey(document.getElementById("sp-key-run")),
-       LayoutHelpers.prettyKey(document.getElementById("sp-key-inspect")),
-       LayoutHelpers.prettyKey(document.getElementById("sp-key-display"))],
+      [DevtoolsHelpers.prettyKey(document.getElementById("sp-key-run")),
+       DevtoolsHelpers.prettyKey(document.getElementById("sp-key-inspect")),
+       DevtoolsHelpers.prettyKey(document.getElementById("sp-key-display"))],
       3);
 
     let args = window.arguments;
diff --git a/browser/devtools/shared/test/browser_layoutHelpers.js b/browser/devtools/shared/test/browser_layoutHelpers.js
index 6f421474ded..a626d0a6040 100644
--- a/browser/devtools/shared/test/browser_layoutHelpers.js
+++ b/browser/devtools/shared/test/browser_layoutHelpers.js
@@ -25,52 +25,54 @@ function test() {
 }
 
 function runTest(win, some) {
+  let lh = new LayoutHelpers(win);
+
   some.style.top = win.innerHeight + 'px';
   some.style.left = win.innerWidth + 'px';
   // The tests start with a black 2x2 pixels square below bottom right.
   // Do not resize the window during the tests.
 
   win.scroll(win.innerWidth / 2, win.innerHeight + 2);  // Above the viewport.
-  LayoutHelpers.scrollIntoViewIfNeeded(some);
+  lh.scrollIntoViewIfNeeded(some);
   is(win.scrollY, Math.floor(win.innerHeight / 2) + 1,
      'Element completely hidden above should appear centered.');
 
   win.scroll(win.innerWidth / 2, win.innerHeight + 1);  // On the top edge.
-  LayoutHelpers.scrollIntoViewIfNeeded(some);
+  lh.scrollIntoViewIfNeeded(some);
   is(win.scrollY, win.innerHeight,
      'Element partially visible above should appear above.');
 
   win.scroll(win.innerWidth / 2, 0);  // Just below the viewport.
-  LayoutHelpers.scrollIntoViewIfNeeded(some);
+  lh.scrollIntoViewIfNeeded(some);
   is(win.scrollY, Math.floor(win.innerHeight / 2) + 1,
      'Element completely hidden below should appear centered.');
 
   win.scroll(win.innerWidth / 2, 1);  // On the bottom edge.
-  LayoutHelpers.scrollIntoViewIfNeeded(some);
+  lh.scrollIntoViewIfNeeded(some);
   is(win.scrollY, 2,
      'Element partially visible below should appear below.');
 
 
   win.scroll(win.innerWidth / 2, win.innerHeight + 2);  // Above the viewport.
-  LayoutHelpers.scrollIntoViewIfNeeded(some, false);
+  lh.scrollIntoViewIfNeeded(some, false);
   is(win.scrollY, win.innerHeight,
      'Element completely hidden above should appear above ' +
      'if parameter is false.');
 
   win.scroll(win.innerWidth / 2, win.innerHeight + 1);  // On the top edge.
-  LayoutHelpers.scrollIntoViewIfNeeded(some, false);
+  lh.scrollIntoViewIfNeeded(some, false);
   is(win.scrollY, win.innerHeight,
      'Element partially visible above should appear above ' +
      'if parameter is false.');
 
   win.scroll(win.innerWidth / 2, 0);  // Below the viewport.
-  LayoutHelpers.scrollIntoViewIfNeeded(some, false);
+  lh.scrollIntoViewIfNeeded(some, false);
   is(win.scrollY, 2,
      'Element completely hidden below should appear below ' +
      'if parameter is false.');
 
   win.scroll(win.innerWidth / 2, 1);  // On the bottom edge.
-  LayoutHelpers.scrollIntoViewIfNeeded(some, false);
+  lh.scrollIntoViewIfNeeded(some, false);
   is(win.scrollY, 2,
      'Element partially visible below should appear below ' +
      'if parameter is false.');
@@ -86,7 +88,7 @@ function runTest(win, some) {
 
   fwin.addEventListener('load', function frameLoad() {
     let some = fwin.document.getElementById('some');
-    LayoutHelpers.scrollIntoViewIfNeeded(some);
+    lh.scrollIntoViewIfNeeded(some);
     is(win.scrollX, Math.floor(win.innerWidth / 2) + 20,
        'Scrolling from an iframe should center the iframe vertically.');
     is(win.scrollY, Math.floor(win.innerHeight / 2) + 20,
diff --git a/browser/devtools/tilt/test/browser_tilt_utils05.js b/browser/devtools/tilt/test/browser_tilt_utils05.js
index 0f09d198e94..139b4aa3c2d 100644
--- a/browser/devtools/tilt/test/browser_tilt_utils05.js
+++ b/browser/devtools/tilt/test/browser_tilt_utils05.js
@@ -55,10 +55,11 @@ function test() {
       iframe.contentWindow.innerHeight,
       "The content window height wasn't calculated correctly.");
 
-    let nodeCoordinates = LayoutHelpers.getRect(
+    let lh = new LayoutHelpers(gBrowser.contentWindow);
+    let nodeCoordinates = lh.getRect(
       iframe.contentDocument.getElementById("test-div"), iframe.contentWindow);
 
-    let frameOffset = LayoutHelpers.getIframeContentOffset(iframe);
+    let frameOffset = lh.getIframeContentOffset(iframe);
     let frameRect = iframe.getBoundingClientRect();
 
     is(nodeCoordinates.top, frameRect.top + frameOffset[0] + 98,
diff --git a/browser/devtools/tilt/test/browser_tilt_utils07.js b/browser/devtools/tilt/test/browser_tilt_utils07.js
index 0c07300a896..ab97cc698ef 100644
--- a/browser/devtools/tilt/test/browser_tilt_utils07.js
+++ b/browser/devtools/tilt/test/browser_tilt_utils07.js
@@ -104,10 +104,11 @@ function test() {
       iframe.contentWindow.innerHeight,
       "The content window height wasn't calculated correctly.");
 
-    let nodeCoordinates = LayoutHelpers.getRect(
+    let lh = new LayoutHelpers(gBrowser.contentWindow);
+    let nodeCoordinates = lh.getRect(
       iframe.contentDocument.getElementById("test-div"), iframe.contentWindow);
 
-    let frameOffset = LayoutHelpers.getIframeContentOffset(iframe);
+    let frameOffset = lh.getIframeContentOffset(iframe);
     let frameRect = iframe.getBoundingClientRect();
 
     is(nodeCoordinates.top, frameRect.top + frameOffset[0],
diff --git a/browser/devtools/tilt/tilt-utils.js b/browser/devtools/tilt/tilt-utils.js
index 40f3613b6e0..17e14644f95 100644
--- a/browser/devtools/tilt/tilt-utils.js
+++ b/browser/devtools/tilt/tilt-utils.js
@@ -405,8 +405,9 @@ TiltUtils.DOM = {
    */
   getNodePosition: function TUD_getNodePosition(aContentWindow, aNode,
                                                 aParentPosition) {
+    let lh = new LayoutHelpers(aContentWindow);
     // get the x, y, width and height coordinates of the node
-    let coord = LayoutHelpers.getRect(aNode, aContentWindow);
+    let coord = lh.getRect(aNode, aContentWindow);
     if (!coord) {
       return null;
     }