diff --git a/browser/base/content/test/browser_bug420160.js b/browser/base/content/test/browser_bug420160.js
index c1dcbe6f0b5d..ab601db8c3b5 100644
--- a/browser/base/content/test/browser_bug420160.js
+++ b/browser/base/content/test/browser_bug420160.js
@@ -1,49 +1,42 @@
 var listener = {
-  testFunction : null,
-  
-  handleEvent : function (e) {
+  testFunction: null,
+
+  handleEvent: function (e) {
     this.testFunction();
   }
 }
 
-var newBrowser;
-
 /* Tests for correct behaviour of getEffectiveHost on identity handler */
 function test() {
-  
   waitForExplicitFinish();
-  
+
   ok(gIdentityHandler, "gIdentityHandler should exist");
-  
-  var newTab = gBrowser.addTab();
-  gBrowser.selectedTab = newTab;
-  newBrowser = gBrowser.getBrowserForTab(newTab);
-  
-  newBrowser.addEventListener("load", listener, true);
+
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", listener, true);
   listener.testFunction = testNormalDomain;  
-  newBrowser.contentWindow.location = 'http://test1.example.org/';
+  content.location = "http://test1.example.org/";
 }
 
 function testNormalDomain() {
   is(gIdentityHandler._lastLocation.host, 'test1.example.org', "Identity handler is getting the full location");
   is(gIdentityHandler.getEffectiveHost(), 'example.org', "getEffectiveHost should return example.org for test1.example.org");
-  
+
   listener.testFunction = testNormalDomainWithPort;
-  newBrowser.contentWindow.location = 'http://sub1.test1.example.org:8000/';
+  content.location = "http://sub1.test1.example.org:8000/";
 }
 
 function testNormalDomainWithPort() {
-
   is(gIdentityHandler._lastLocation.host, 'sub1.test1.example.org:8000', "Identity handler is getting port information");
   is(gIdentityHandler.getEffectiveHost(), 'example.org', "getEffectiveHost should return example.org for sub1.test1.example.org:8000");
-  
+
   listener.testFunction = testIPWithPort;
-  newBrowser.contentWindow.location = 'http://127.0.0.1:8888/';
+  content.location = "http://127.0.0.1:8888/";
 }
 
 function testIPWithPort() {
   is(gIdentityHandler.getEffectiveHost(), '127.0.0.1', "getEffectiveHost should return 127.0.0.1 for 127.0.0.1:8888");
-  newBrowser.removeEventListener("load", listener, true);
+  gBrowser.selectedBrowser.removeEventListener("load", listener, true);
   gBrowser.removeCurrentTab();
   finish();
 }
diff --git a/browser/base/content/test/browser_bug423833.js b/browser/base/content/test/browser_bug423833.js
index 7980502f5cea..8b45585265e7 100644
--- a/browser/base/content/test/browser_bug423833.js
+++ b/browser/base/content/test/browser_bug423833.js
@@ -5,9 +5,6 @@ var invalidPage = 'http://127.0.0.1:55555/';
 var validPage = 'http://example.com/';
 var testPage = 'data:text/html,<frameset cols="400,400"><frame src="' + validPage + '"><frame src="' + invalidPage + '"></frameset>';
 
-// Keep track of the browser inside our frame
-var newBrowser;
-
 // Store the tab and window created in tests 2 and 3 respectively
 var test2tab;
 var test3window;
@@ -16,87 +13,80 @@ var test3window;
 var intervalID;
 
 function test() {
-  
   waitForExplicitFinish();
-  
-  var newTab = gBrowser.addTab();
-  gBrowser.selectedTab = newTab;
-  newBrowser = gBrowser.getBrowserForTab(newTab);
-  
-  newBrowser.addEventListener("load", test1Setup, true);
-  newBrowser.contentWindow.location = testPage;
+
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", test1Setup, true);
+  content.location = testPage;
 }
 
 function test1Setup() {
-  
-  if(newBrowser.contentWindow.frames.length < 2 ||
-     newBrowser.contentWindow.frames[1].document.location != invalidPage)
+  if (content.frames.length < 2 ||
+      content.frames[1].location != invalidPage)
     // The error frame hasn't loaded yet
     return;
-  
-  newBrowser.removeEventListener("load", test1Setup, true);
 
-  var badFrame = newBrowser.contentWindow.frames[1];
+  gBrowser.selectedBrowser.removeEventListener("load", test1Setup, true);
+
+  var badFrame = content.frames[1];
   document.popupNode = badFrame.document.firstChild;
-  
+
   var contentAreaContextMenu = document.getElementById("contentAreaContextMenu");
   var contextMenu = new nsContextMenu(contentAreaContextMenu, gBrowser);
 
   // We'd like to use another load listener here, but error pages don't fire load events
   contextMenu.showOnlyThisFrame();
-  intervalID = window.setInterval(testShowOnlyThisFrame, 3000);
+  intervalID = setInterval(testShowOnlyThisFrame, 3000);
 }
 
 function testShowOnlyThisFrame() {
-  
-  if(newBrowser.contentDocument.location.href == testPage)
+  if (content.location.href == testPage)
     // This is a stale event from the original page loading
     return;
-  
+
   // We should now have loaded the error page frame content directly
   // in the tab, make sure the URL is right.
-  window.clearInterval(intervalID);
-  
-  is(newBrowser.contentDocument.location.href, invalidPage, "Should navigate to page url, not about:neterror");
-  
+  clearInterval(intervalID);
+
+  is(content.location.href, invalidPage, "Should navigate to page url, not about:neterror");
+
   // Go back to the frames page
   gBrowser.addEventListener("load", test2Setup, true);
-  newBrowser.contentWindow.location = testPage;
+  content.location = testPage;
 }
 
 function test2Setup() {
-  if(newBrowser.contentWindow.frames.length < 2 ||
-     newBrowser.contentWindow.frames[1].document.location != invalidPage)
+  if (content.frames.length < 2 ||
+      content.frames[1].location != invalidPage)
     // The error frame hasn't loaded yet
     return;
-  
+
   gBrowser.removeEventListener("load", test2Setup, true);
-  
+
   // Now let's do the whole thing again, but this time for "Open frame in new tab"
-  newBrowser = gBrowser.getBrowserForTab(gBrowser.selectedTab);
-  var badFrame = newBrowser.contentWindow.frames[1];
-  
+  var badFrame = content.frames[1];
+
   document.popupNode = badFrame.document.firstChild;
-  
+
   var contentAreaContextMenu = document.getElementById("contentAreaContextMenu");
   var contextMenu = new nsContextMenu(contentAreaContextMenu, gBrowser);
 
   test2tab = contextMenu.openFrameInTab();
   ok(test2tab instanceof XULElement, "openFrameInTab() should return an element (non-null)");
   is(test2tab.tagName, "tab", "openFrameInTab() should return a *tab* element");
-  
+
   gBrowser.selectedTab = test2tab;
 
-  intervalID = window.setInterval(testOpenFrameInTab, 3000);
+  intervalID = setInterval(testOpenFrameInTab, 3000);
 }
 
 function testOpenFrameInTab() {
-  
-  if(gBrowser.contentDocument.location.href == "about:blank")
+  if (gBrowser.contentDocument.location.href == "about:blank")
     // Wait another cycle
     return;
-  window.clearInterval(intervalID);
-  
+
+  clearInterval(intervalID);
+
   // We should now have the error page in a new, active tab.
   is(gBrowser.contentDocument.location.href, invalidPage, "New tab should have page url, not about:neterror");
 
@@ -107,30 +97,28 @@ function testOpenFrameInTab() {
 }
 
 function test3Setup() {
-
   // One more time, for "Open frame in new window"
-  newBrowser = gBrowser.getBrowserForTab(gBrowser.selectedTab);
-  var badFrame = newBrowser.contentWindow.frames[1];
+  var badFrame = content.frames[1];
   document.popupNode = badFrame.document.firstChild;
-  
+
   var contentAreaContextMenu = document.getElementById("contentAreaContextMenu");
   var contextMenu = new nsContextMenu(contentAreaContextMenu, gBrowser);
 
   test3window = contextMenu.openFrame();
   ok(test3window instanceof Window, "openFrame() should return a window (non-null) ");
-  
-  intervalID = window.setInterval(testOpenFrame, 3000);
+
+  intervalID = setInterval(testOpenFrame, 3000);
 }
 
 function testOpenFrame() {
-  
-  if(test3window.content.document.location.href == "about:blank")
+  if (test3window.content.location.href == "about:blank")
     // Wait another cycle
     return;
-  window.clearInterval(intervalID);
-     
-  is(test3window.content.document.location.href, invalidPage, "New window should have page url, not about:neterror");
-  
+
+  clearInterval(intervalID);
+
+  is(test3window.content.location.href, invalidPage, "New window should have page url, not about:neterror");
+
   test3window.close();
   cleanup();
 }
diff --git a/browser/base/content/test/browser_bug424101.js b/browser/base/content/test/browser_bug424101.js
index 622b1f6106cb..c06fe4d4ae45 100644
--- a/browser/base/content/test/browser_bug424101.js
+++ b/browser/base/content/test/browser_bug424101.js
@@ -4,12 +4,11 @@ function test() {
   waitForExplicitFinish();
 
   gBrowser.selectedTab = gBrowser.addTab();
-  let newBrowser = gBrowser.selectedBrowser;
   
-  newBrowser.addEventListener("load", function() {
-    newBrowser.removeEventListener("load", arguments.callee, true);
+  gBrowser.selectedBrowser.addEventListener("load", function() {
+    gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
 
-    let doc = newBrowser.contentDocument;
+    let doc = gBrowser.contentDocument;
     let testInput = function(type, expected) {
       let element = doc.createElement("input");
       element.setAttribute("type", type);
@@ -50,5 +49,5 @@ function test() {
     gBrowser.removeCurrentTab();
     finish();
   }, true);
-  newBrowser.loadURI("data:text/html,test");
+  content.location = "data:text/html,test";
 }
diff --git a/browser/base/content/test/browser_bug427559.js b/browser/base/content/test/browser_bug427559.js
index 325b9e13dd59..fe5a51e94440 100644
--- a/browser/base/content/test/browser_bug427559.js
+++ b/browser/base/content/test/browser_bug427559.js
@@ -46,28 +46,26 @@ let testPage = 'data:text/html,<body><button onblur="this.parentNode.removeChild
 function test() {
   waitForExplicitFinish();
 
-  // Prepare the test tab
-  let testTab = gBrowser.addTab();
-  gBrowser.selectedTab = testTab;
-  let testBrowser = gBrowser.getBrowserForTab(testTab);
+  gBrowser.selectedTab = gBrowser.addTab();
 
-  // Do stuff just after the page loads, so the page script can do its stuff
-  testBrowser.addEventListener("load", function() setTimeout(function() {
-    // The test page loaded, so open an empty tab, select it, then restore
-    // the test tab. This causes the test page's focused element to be removed
-    // from its document.
-    let emptyTab = gBrowser.addTab();
-    gBrowser.selectedTab = emptyTab;
-    gBrowser.removeCurrentTab();
-    gBrowser.selectedTab = testTab;
+  gBrowser.selectedBrowser.addEventListener("load", function () {
+    setTimeout(function () {
+      var testPageWin = content;
 
-    // Make sure focus is given to the window because the element is now gone
-    is(document.commandDispatcher.focusedWindow, window.content,
-       "content window is focused");
-    gBrowser.removeCurrentTab();
-    finish();
-  }, 0), true);
+      // The test page loaded, so open an empty tab, select it, then restore
+      // the test tab. This causes the test page's focused element to be removed
+      // from its document.
+      gBrowser.selectedTab = gBrowser.addTab();
+      gBrowser.removeCurrentTab();
 
-  // Start the test by loading the test page
-  testBrowser.contentWindow.location = testPage;
+      // Make sure focus is given to the window because the element is now gone
+      is(document.commandDispatcher.focusedWindow, testPageWin,
+         "content window is focused");
+
+      gBrowser.removeCurrentTab();
+      finish();
+    }, 0);
+  }, true);
+
+  content.location = testPage;
 }
diff --git a/browser/base/content/test/browser_sanitize-timespans.js b/browser/base/content/test/browser_sanitize-timespans.js
index 0e69bede45da..9bc45b6597ea 100644
--- a/browser/base/content/test/browser_sanitize-timespans.js
+++ b/browser/base/content/test/browser_sanitize-timespans.js
@@ -47,7 +47,7 @@ function test() {
   ok(bhist.isVisited(makeURI("http://4hour.com")), "Pretend visit to 4hour.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should still exist");
   
-  if(minutesSinceMidnight > 10)
+  if (minutesSinceMidnight > 10)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
@@ -58,7 +58,7 @@ function test() {
   ok(formhist.nameExists("2hour10minutes"), "2hour10minutes form entry should still exist");
   ok(formhist.nameExists("4hour"), "4hour form entry should still exist");
   ok(formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should still exist");
-  if(minutesSinceMidnight > 10)
+  if (minutesSinceMidnight > 10)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
@@ -71,7 +71,7 @@ function test() {
   ok(downloadExists(5555553), "<4 hour old download should still be present");
   ok(downloadExists(5555558), "4 hour 10 minute download should still be present");
 
-  if(minutesSinceMidnight > 10)
+  if (minutesSinceMidnight > 10)
     ok(downloadExists(5555554), "'Today' download should still be present");
 
   // Clear 1 hour
@@ -85,7 +85,7 @@ function test() {
   ok(bhist.isVisited(makeURI("http://4hour.com")), "Pretend visit to 4hour.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should still exist");
   
-  if(hoursSinceMidnight > 1)
+  if (hoursSinceMidnight > 1)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
@@ -95,7 +95,7 @@ function test() {
   ok(formhist.nameExists("2hour10minutes"), "2hour10minutes form entry should still exist");
   ok(formhist.nameExists("4hour"), "4hour form entry should still exist");
   ok(formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should still exist");
-  if(hoursSinceMidnight > 1)
+  if (hoursSinceMidnight > 1)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
@@ -107,7 +107,7 @@ function test() {
   ok(downloadExists(5555553), "<4 hour old download should still be present");
   ok(downloadExists(5555558), "4 hour 10 minute download should still be present");
 
-  if(hoursSinceMidnight > 1)
+  if (hoursSinceMidnight > 1)
     ok(downloadExists(5555554), "'Today' download should still be present");
   
   // Clear 1 hour 10 minutes
@@ -120,7 +120,7 @@ function test() {
   ok(bhist.isVisited(makeURI("http://2hour10minutes.com/")), "Pretend visit to 2hour10minutes.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour.com")), "Pretend visit to 4hour.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should still exist");
-  if(minutesSinceMidnight > 70)
+  if (minutesSinceMidnight > 70)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
@@ -129,7 +129,7 @@ function test() {
   ok(formhist.nameExists("2hour10minutes"), "2hour10minutes form entry should still exist");
   ok(formhist.nameExists("4hour"), "4hour form entry should still exist");
   ok(formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should still exist");
-  if(minutesSinceMidnight > 70)
+  if (minutesSinceMidnight > 70)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
@@ -139,7 +139,7 @@ function test() {
   ok(downloadExists(5555557), "2 hour 10 minute download should still be present");
   ok(downloadExists(5555553), "<4 hour old download should still be present");
   ok(downloadExists(5555558), "4 hour 10 minute download should still be present");
-  if(minutesSinceMidnight > 70)
+  if (minutesSinceMidnight > 70)
     ok(downloadExists(5555554), "'Today' download should still be present");
 
   // Clear 2 hours
@@ -150,7 +150,7 @@ function test() {
   ok(bhist.isVisited(makeURI("http://2hour10minutes.com/")), "Pretend visit to 2hour10minutes.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour.com")), "Pretend visit to 4hour.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should still exist");
-  if(hoursSinceMidnight > 2)
+  if (hoursSinceMidnight > 2)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
@@ -158,7 +158,7 @@ function test() {
   ok(formhist.nameExists("2hour10minutes"), "2hour10minutes form entry should still exist");
   ok(formhist.nameExists("4hour"), "4hour form entry should still exist");
   ok(formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should still exist");
-  if(hoursSinceMidnight > 2)
+  if (hoursSinceMidnight > 2)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
@@ -168,7 +168,7 @@ function test() {
   ok(downloadExists(5555557), "2 hour 10 minute download should still be present");
   ok(downloadExists(5555553), "<4 hour old download should still be present");
   ok(downloadExists(5555558), "4 hour 10 minute download should still be present");
-  if(hoursSinceMidnight > 2)
+  if (hoursSinceMidnight > 2)
     ok(downloadExists(5555554), "'Today' download should still be present");
   
   // Clear 2 hours 10 minutes
@@ -179,14 +179,14 @@ function test() {
   ok(!bhist.isVisited(makeURI("http://2hour10minutes.com")), "Pretend visit to 2hour10minutes.com should now be deleted");
   ok(bhist.isVisited(makeURI("http://4hour.com")), "Pretend visit to 4hour.com should still exist");
   ok(bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should still exist");
-  if(minutesSinceMidnight > 130)
+  if (minutesSinceMidnight > 130)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
   ok(!formhist.nameExists("2hour10minutes"), "2hour10minutes form entry should be deleted");
   ok(formhist.nameExists("4hour"), "4hour form entry should still exist");
   ok(formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should still exist");
-  if(minutesSinceMidnight > 130)
+  if (minutesSinceMidnight > 130)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
@@ -194,7 +194,7 @@ function test() {
   ok(downloadExists(5555553), "<4 hour old download should still be present");
   ok(downloadExists(5555558), "4 hour 10 minute download should still be present");
   ok(downloadExists(5555550), "Year old download should still be present");
-  if(minutesSinceMidnight > 130)
+  if (minutesSinceMidnight > 130)
     ok(downloadExists(5555554), "'Today' download should still be present");
 
   // Clear 4 hours
@@ -203,20 +203,20 @@ function test() {
   
   ok(!bhist.isVisited(makeURI("http://4hour.com")), "Pretend visit to 4hour.com should now be deleted");
   ok(bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should still exist");
-  if(hoursSinceMidnight > 4)
+  if (hoursSinceMidnight > 4)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
   ok(!formhist.nameExists("4hour"), "4hour form entry should be deleted");
   ok(formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should still exist");
-  if(hoursSinceMidnight > 4)
+  if (hoursSinceMidnight > 4)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
   ok(!downloadExists(5555553), "<4 hour old download should now be deleted");
   ok(downloadExists(5555558), "4 hour 10 minute download should still be present");
   ok(downloadExists(5555550), "Year old download should still be present");
-  if(hoursSinceMidnight > 4)
+  if (hoursSinceMidnight > 4)
     ok(downloadExists(5555554), "'Today' download should still be present");
 
   // Clear 4 hours 10 minutes
@@ -225,18 +225,18 @@ function test() {
   s.range = null;
   
   ok(!bhist.isVisited(makeURI("http://4hour10minutes.com/")), "Pretend visit to 4hour10minutes.com should now be deleted");
-  if(minutesSinceMidnight > 250)
+  if (minutesSinceMidnight > 250)
     ok(bhist.isVisited(makeURI("http://today.com")), "Pretend visit to today.com should still exist");
   ok(bhist.isVisited(makeURI("http://before-today.com")), "Pretend visit to before-today.com should still exist");
   
   ok(!formhist.nameExists("4hour10minutes"), "4hour10minutes form entry should be deleted");
-  if(minutesSinceMidnight > 250)
+  if (minutesSinceMidnight > 250)
     ok(formhist.nameExists("today"), "today form entry should still exist");
   ok(formhist.nameExists("b4today"), "b4today form entry should still exist");
 
   ok(!downloadExists(5555558), "4 hour 10 minute download should now be deleted");
   ok(downloadExists(5555550), "Year old download should still be present");
-  if(minutesSinceMidnight > 250)
+  if (minutesSinceMidnight > 250)
     ok(downloadExists(5555554), "'Today' download should still be present");
 
   // Clear Today
diff --git a/browser/base/content/test/browser_tabfocus.js b/browser/base/content/test/browser_tabfocus.js
index 58411b8e6b03..b311ff9a24c3 100644
--- a/browser/base/content/test/browser_tabfocus.js
+++ b/browser/base/content/test/browser_tabfocus.js
@@ -55,7 +55,7 @@ function test() {
                      "focusedElement after tab change, focus in url field, no focus in new tab");
 
     // focusing a button in the current tab should focus it
-    var button1 = browser1.contentWindow.document.getElementById("button1");
+    var button1 = browser1.contentDocument.getElementById("button1");
     expectFocusShift(function () button1.focus(),
                      browser1.contentWindow, button1, true,
                      "focusedWindow after focus in focused tab");
@@ -63,7 +63,7 @@ function test() {
     // focusing a button in a background tab should not change the actual
     // focus, but should set the focus that would be in that background tab to
     // that button.
-    var button2 = browser2.contentWindow.document.getElementById("button2");
+    var button2 = browser2.contentDocument.getElementById("button2");
     button2.focus();
 
     expectFocusShift(function () button2.focus(),
diff --git a/browser/components/certerror/test/browser_bug431826.js b/browser/components/certerror/test/browser_bug431826.js
index 02cdea50a81e..cfead3bc9e98 100644
--- a/browser/components/certerror/test/browser_bug431826.js
+++ b/browser/components/certerror/test/browser_bug431826.js
@@ -1,45 +1,40 @@
-var newBrowser
-
 function test() {
   waitForExplicitFinish();
-  
-  var newTab = gBrowser.addTab();
-  gBrowser.selectedTab = newTab;
-  newBrowser = gBrowser.getBrowserForTab(newTab);
-  
+
+  gBrowser.selectedTab = gBrowser.addTab();
+
   // Navigate to a site with a broken cert
   window.addEventListener("DOMContentLoaded", testBrokenCert, true);
-  newBrowser.contentWindow.location = 'https://nocert.example.com/';
+  content.location = "https://nocert.example.com/";
 }
 
 function testBrokenCert() {
   window.removeEventListener("DOMContentLoaded", testBrokenCert, true);
-  
+
   // Confirm that we are displaying the contributed error page, not the default
-  ok(/^about:certerror/.test(gBrowser.contentWindow.document.documentURI), "Broken page should go to about:certerror, not about:neterror");
-  
+  ok(/^about:certerror/.test(gBrowser.contentDocument.documentURI), "Broken page should go to about:certerror, not about:neterror");
+
   // Confirm that the expert section is collapsed
-  var expertDiv = gBrowser.contentWindow.document.getElementById("expertContent");
+  var expertDiv = gBrowser.contentDocument.getElementById("expertContent");
   ok(expertDiv, "Expert content div should exist");
   ok(expertDiv.hasAttribute("collapsed"), "Expert content should be collapsed by default");
-  
+
   // Tweak the expert mode pref
-  Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch)
-                                          .setBoolPref("browser.xul.error_pages.expert_bad_cert", true);
-  
+  gPrefService.setBoolPref("browser.xul.error_pages.expert_bad_cert", true);
+
   window.addEventListener("DOMContentLoaded", testExpertPref, true);
-  newBrowser.reload();
+  gBrowser.reload();
 }
 
 function testExpertPref() {
-  
   window.removeEventListener("DOMContentLoaded", testExpertPref, true);
-  var expertDiv = gBrowser.contentWindow.document.getElementById("expertContent");
-  var technicalDiv = gBrowser.contentWindow.document.getElementById("technicalContent");
+  var expertDiv = gBrowser.contentDocument.getElementById("expertContent");
+  var technicalDiv = gBrowser.contentDocument.getElementById("technicalContent");
   ok(!expertDiv.hasAttribute("collapsed"), "Expert content should not be collapsed with the expert mode pref set");
   ok(!technicalDiv.hasAttribute("collapsed"), "Technical content should not be collapsed with the expert mode pref set");
-  
+
   // Clean up
   gBrowser.removeCurrentTab();
+  gPrefService.clearUserPref("browser.xul.error_pages.expert_bad_cert");
   finish();
 }
diff --git a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_geoprompt.js b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_geoprompt.js
index 82abe577ae66..c7ef5e6e9ff6 100644
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_geoprompt.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_geoprompt.js
@@ -47,50 +47,46 @@ function test() {
     "browser/components/privatebrowsing/test/browser/browser_privatebrowsing_geoprompt_page.html";
   waitForExplicitFinish();
 
-  let pageTab = gBrowser.addTab();
-  gBrowser.selectedTab = pageTab;
-  let pageBrowser = gBrowser.getBrowserForTab(pageTab);
-  pageBrowser.addEventListener("load", function () {
-    pageBrowser.removeEventListener("load", arguments.callee, true);
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", function () {
+    gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
 
     setTimeout(function() {
       // Make sure the notification is correctly displayed with a remember control
-      let notificationBox = gBrowser.getNotificationBox(pageBrowser);
+      let notificationBox = gBrowser.getNotificationBox();
       let notification = notificationBox.getNotificationWithValue("geolocation");
       ok(notification, "Notification box should be displaying outside of private browsing mode");
       is(notification.getElementsByClassName("rememberChoice").length, 1,
          "The remember control must be displayed outside of private browsing mode");
       notificationBox.currentNotification.close();
 
-      gBrowser.removeTab(pageTab);
+      gBrowser.removeCurrentTab();
 
       // enter the private browsing mode
       pb.privateBrowsingEnabled = true;
 
-      pageTab = gBrowser.addTab();
-      gBrowser.selectedTab = pageTab;
-      pageBrowser = gBrowser.getBrowserForTab(pageTab);
-      pageBrowser.addEventListener("load", function () {
-        pageBrowser.removeEventListener("load", arguments.callee, true);
+      gBrowser.selectedTab = gBrowser.addTab();
+      gBrowser.selectedBrowser.addEventListener("load", function () {
+        gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
 
-        setTimeout(function() {
+        setTimeout(function () {
           // Make sure the notification is correctly displayed without a remember control
-          let notificationBox = gBrowser.getNotificationBox(pageBrowser);
+          let notificationBox = gBrowser.getNotificationBox();
           let notification = notificationBox.getNotificationWithValue("geolocation");
           ok(notification, "Notification box should be displaying outside of private browsing mode");
           is(notification.getElementsByClassName("rememberChoice").length, 0,
              "The remember control must not be displayed inside of private browsing mode");
           notificationBox.currentNotification.close();
 
-          gBrowser.removeTab(pageTab);
+          gBrowser.removeCurrentTab();
 
           // cleanup
           pb.privateBrowsingEnabled = false;
           finish();
         }, 100); // remember control is added in a setTimeout(0) call
       }, true);
-      pageBrowser.contentWindow.location = testPageURL;
+      content.location = testPageURL;
     }, 100); // remember control is added in a setTimeout(0) call
   }, true);
-  pageBrowser.contentWindow.location = testPageURL;
+  content.location = testPageURL;
 }
diff --git a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_openlocation.js b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_openlocation.js
index d595782ebd74..48a696bebd2c 100644
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_openlocation.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_openlocation.js
@@ -55,7 +55,7 @@ function test() {
           dialog.addEventListener("load", function () {
             dialog.removeEventListener("load", arguments.callee, false);
 
-            let browser = gBrowser.getBrowserForTab(gBrowser.selectedTab);
+            let browser = gBrowser.selectedBrowser;
             browser.addEventListener("load", function() {
               browser.removeEventListener("load", arguments.callee, true);
 
diff --git a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_sslsite_transition.js b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_sslsite_transition.js
index 0556d037032e..3b2e02b4ee99 100644
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_sslsite_transition.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_sslsite_transition.js
@@ -40,18 +40,15 @@
 
 function test() {
   // initialization
-  let prefBranch = Cc["@mozilla.org/preferences-service;1"].
-                   getService(Ci.nsIPrefBranch);
-  prefBranch.setBoolPref("browser.privatebrowsing.keep_current_session", true);
+  gPrefService.setBoolPref("browser.privatebrowsing.keep_current_session", true);
   let pb = Cc["@mozilla.org/privatebrowsing;1"].
            getService(Ci.nsIPrivateBrowsingService);
 
-  const kTestURL = "https://example.com/";
+  const TEST_URL = "https://example.com/";
 
   // load an SSL site in the first tab and wait for it to finish loading
-  let tab = gBrowser.addTab();
-  gBrowser.selectedTab = tab;
-  let browser = gBrowser.getBrowserForTab(tab);
+  gBrowser.selectedTab = gBrowser.addTab();
+  let browser = gBrowser.selectedBrowser;
   browser.addEventListener("load", function() {
     browser.removeEventListener("load", arguments.callee, true);
 
@@ -62,19 +59,19 @@ function test() {
     browser.addEventListener("load", function() {
       browser.removeEventListener("load", arguments.callee, true);
 
-      is(browser.contentWindow.location, kTestURL,
+      is(content.location, TEST_URL,
         "The original SSL page should be loaded at this stage");
 
-      gBrowser.removeTab(tab);
-      prefBranch.clearUserPref("browser.privatebrowsing.keep_current_session");
+      gBrowser.removeCurrentTab();
+      gPrefService.clearUserPref("browser.privatebrowsing.keep_current_session");
       finish();
     }, true);
 
-    executeSoon(function(){
-      browser.contentWindow.location = kTestURL;
+    executeSoon(function () {
+      content.location = TEST_URL;
     });
   }, true);
-  browser.contentWindow.location = kTestURL;
+  content.location = TEST_URL;
 
   waitForExplicitFinish();
 }
diff --git a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_urlbarfocus.js b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_urlbarfocus.js
index f234e9c5e7da..e130da13178f 100644
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_urlbarfocus.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_urlbarfocus.js
@@ -42,10 +42,9 @@ function test() {
   let pb = Cc["@mozilla.org/privatebrowsing;1"].
            getService(Ci.nsIPrivateBrowsingService);
 
-  const kTestURL = "data:text/plain,test";
-  let tab = gBrowser.addTab();
-  gBrowser.selectedTab = tab;
-  let browser = gBrowser.getBrowserForTab(tab);
+  const TEST_URL = "data:text/plain,test";
+  gBrowser.selectedTab = gBrowser.addTab();
+  let browser = gBrowser.selectedBrowser;
   browser.addEventListener("load", function() {
     browser.removeEventListener("load", arguments.callee, true);
 
@@ -58,8 +57,7 @@ function test() {
 
     // enter private browsing mode
     pb.privateBrowsingEnabled = true;
-    tab = gBrowser.selectedTab;
-    browser = gBrowser.getBrowserForTab(tab);
+    browser = gBrowser.selectedBrowser;
     browser.addEventListener("load", function() {
       // setTimeout is needed here because the onload handler of about:privatebrowsing sets the focus
       setTimeout(function() {
@@ -71,8 +69,7 @@ function test() {
 
         // leave private browsing mode
         pb.privateBrowsingEnabled = false;
-        tab = gBrowser.selectedTab;
-        browser = gBrowser.getBrowserForTab(tab);
+        browser = gBrowser.selectedBrowser;
         browser.addEventListener("load", function() {
           // ensure that the URL bar is no longer focused after leaving the private browsing mode
           isnot(document.commandDispatcher.focusedElement, gURLBar.inputField,
@@ -80,13 +77,13 @@ function test() {
           // ensure that the URL bar is no longer empty after leaving the private browsing mode
           isnot(gURLBar.value, "", "URL Bar should no longer be empty after leaving the private browsing mode");
 
-          gBrowser.removeTab(tab);
+          gBrowser.removeCurrentTab();
           finish();
         }, true);
       }, 0);
     }, true);
   }, true);
-  browser.contentWindow.location = kTestURL;
+  content.location = TEST_URL;
 
   waitForExplicitFinish();
 }
diff --git a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_windowtitle.js b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_windowtitle.js
index f0335efb876d..558502f1bf1a 100644
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_windowtitle.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_windowtitle.js
@@ -40,9 +40,7 @@
 
 function test() {
   // initialization
-  let prefBranch = Cc["@mozilla.org/preferences-service;1"].
-                   getService(Ci.nsIPrefBranch);
-  prefBranch.setBoolPref("browser.privatebrowsing.keep_current_session", true);
+  gPrefService.setBoolPref("browser.privatebrowsing.keep_current_session", true);
   let pb = Cc["@mozilla.org/privatebrowsing;1"].
            getService(Ci.nsIPrivateBrowsingService);
 
@@ -80,9 +78,8 @@ function test() {
   function testTabTitle(url, insidePB, expected_title, funcNext) {
     pb.privateBrowsingEnabled = insidePB;
 
-    let tab = gBrowser.addTab();
-    gBrowser.selectedTab = tab;
-    let browser = gBrowser.getBrowserForTab(tab);
+    let tab = gBrowser.selectedTab = gBrowser.addTab();
+    let browser = gBrowser.selectedBrowser;
     browser.addEventListener("load", function() {
       browser.removeEventListener("load", arguments.callee, true);
 
@@ -117,7 +114,7 @@ function test() {
 
   function cleanup() {
     pb.privateBrowsingEnabled = false;
-    prefBranch.clearUserPref("browser.privatebrowsing.keep_current_session");
+    gPrefService.clearUserPref("browser.privatebrowsing.keep_current_session");
     finish();
   }
 
diff --git a/browser/components/safebrowsing/content/test/browser_bug400731.js b/browser/components/safebrowsing/content/test/browser_bug400731.js
index 8237788fc392..d1306998a664 100644
--- a/browser/components/safebrowsing/content/test/browser_bug400731.js
+++ b/browser/components/safebrowsing/content/test/browser_bug400731.js
@@ -1,41 +1,38 @@
 /* Check for the intended visibility of the "Ignore this warning" text*/
-var newBrowser
 
 function test() {
   waitForExplicitFinish();
   
-  var newTab = gBrowser.addTab();
-  gBrowser.selectedTab = newTab;
-  newBrowser = gBrowser.getBrowserForTab(newTab);
+  gBrowser.selectedTab = gBrowser.addTab();
   
   // Navigate to malware site.  Can't use an onload listener here since
   // error pages don't fire onload
   window.addEventListener("DOMContentLoaded", testMalware, true);
-  newBrowser.contentWindow.location = 'http://www.mozilla.com/firefox/its-an-attack.html';
+  content.location = "http://www.mozilla.com/firefox/its-an-attack.html";
 }
 
 function testMalware() {
   window.removeEventListener("DOMContentLoaded", testMalware, true);
 
   // Confirm that "Ignore this warning" is visible - bug 422410
-  var el = newBrowser.contentDocument.getElementById("ignoreWarningButton");
+  var el = content.document.getElementById("ignoreWarningButton");
   ok(el, "Ignore warning button should be present for malware");
   
-  var style = newBrowser.contentWindow.getComputedStyle(el, null);
+  var style = content.getComputedStyle(el, null);
   is(style.display, "-moz-box", "Ignore Warning button should be display:-moz-box for malware");
   
   // Now launch the phishing test
   window.addEventListener("DOMContentLoaded", testPhishing, true);
-  newBrowser.contentWindow.location = 'http://www.mozilla.com/firefox/its-a-trap.html';
+  content.location = "http://www.mozilla.com/firefox/its-a-trap.html";
 }
 
 function testPhishing() {
   window.removeEventListener("DOMContentLoaded", testPhishing, true);
   
-  var el = newBrowser.contentDocument.getElementById("ignoreWarningButton");
+  var el = content.document.getElementById("ignoreWarningButton");
   ok(el, "Ignore warning button should be present for phishing");
   
-  var style = newBrowser.contentWindow.getComputedStyle(el, null);
+  var style = content.getComputedStyle(el, null);
   is(style.display, "-moz-box", "Ignore Warning button should be display:-moz-box for phishing");
   
   gBrowser.removeCurrentTab();
diff --git a/browser/components/safebrowsing/content/test/browser_bug415846.js b/browser/components/safebrowsing/content/test/browser_bug415846.js
index ed2e2f9696c9..5e7b64e6cc37 100644
--- a/browser/components/safebrowsing/content/test/browser_bug415846.js
+++ b/browser/components/safebrowsing/content/test/browser_bug415846.js
@@ -3,20 +3,16 @@ menu items.
 
 Mac makes this astonishingly painful to test since their help menu is special magic,
 but we can at least test it on the other platforms.*/
-var newBrowser;
 var menu;
 
 function test() {
-
   waitForExplicitFinish();
   
-  var newTab = gBrowser.addTab();
-  gBrowser.selectedTab = newTab;
-  newBrowser = gBrowser.getBrowserForTab(newTab);
+  gBrowser.selectedTab = gBrowser.addTab();
 
   // Navigate to a normal site
   gBrowser.addEventListener("load", testNormal, false);
-  newBrowser.contentWindow.location = 'http://example.com/';
+  content.location = "http://example.com/";
 }
 
 function testNormal() {
@@ -41,7 +37,7 @@ function testNormal_PopupListener() {
   
   // Now launch the phishing test.  Can't use onload here because error pages don't
   // fire normal load events.
-  newBrowser.contentWindow.location = 'http://www.mozilla.com/firefox/its-a-trap.html';
+  content.location = "http://www.mozilla.com/firefox/its-a-trap.html";
   window.setTimeout(testPhishing, 2000);
 }
 
diff --git a/browser/components/sessionstore/test/browser/browser_367052.js b/browser/components/sessionstore/test/browser/browser_367052.js
index 22150755e6f5..14cfa33b74c2 100644
--- a/browser/components/sessionstore/test/browser/browser_367052.js
+++ b/browser/components/sessionstore/test/browser/browser_367052.js
@@ -52,8 +52,7 @@ function test() {
   tab.linkedBrowser.addEventListener("load", function(aEvent) {
     this.removeEventListener("load", arguments.callee, true);
     
-    let browser = tabbrowser.getBrowserForTab(tab);
-    let history = browser.webNavigation.sessionHistory;
+    let history = tab.linkedBrowser.webNavigation.sessionHistory;
     ok(history.count >= 1, "the new tab does have at least one history entry");
     
     ss.setTabState(tab, "{ entries: [] }");