--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -506,39 +506,38 @@ NS_IMETHODIMP
 nsDOMWindowUtils::SendMouseEvent(const nsAString& aType,
                                  float aX,
                                  float aY,
                                  int32_t aButton,
                                  int32_t aClickCount,
                                  int32_t aModifiers,
                                  bool aIgnoreRootScrollFrame,
                                  float aPressure,
-                                 unsigned short aInputSourceArg,
-                                 bool *aPreventDefault)
+                                 unsigned short aInputSourceArg)
 {
   return SendMouseEventCommon(aType, aX, aY, aButton, aClickCount, aModifiers,
                               aIgnoreRootScrollFrame, aPressure,
-                              aInputSourceArg, false, aPreventDefault);
+                              aInputSourceArg, false);
 }
 
 NS_IMETHODIMP
 nsDOMWindowUtils::SendMouseEventToWindow(const nsAString& aType,
                                          float aX,
                                          float aY,
                                          int32_t aButton,
                                          int32_t aClickCount,
                                          int32_t aModifiers,
                                          bool aIgnoreRootScrollFrame,
                                          float aPressure,
                                          unsigned short aInputSourceArg)
 {
   SAMPLE_LABEL("nsDOMWindowUtils", "SendMouseEventToWindow");
   return SendMouseEventCommon(aType, aX, aY, aButton, aClickCount, aModifiers,
                               aIgnoreRootScrollFrame, aPressure,
-                              aInputSourceArg, true, nullptr);
+                              aInputSourceArg, true);
 }
 
 static nsIntPoint
 ToWidgetPoint(float aX, float aY, const nsPoint& aOffset,
               nsPresContext* aPresContext)
 {
   double appPerDev = aPresContext->AppUnitsPerDevPixel();
   nscoord appPerCSS = nsPresContext::AppUnitsPerCSSPixel();
@@ -551,18 +550,17 @@ nsDOMWindowUtils::SendMouseEventCommon(c
                                        float aX,
                                        float aY,
                                        int32_t aButton,
                                        int32_t aClickCount,
                                        int32_t aModifiers,
                                        bool aIgnoreRootScrollFrame,
                                        float aPressure,
                                        unsigned short aInputSourceArg,
-                                       bool aToWindow,
-                                       bool *aPreventDefault)
+                                       bool aToWindow)
 {
   if (!nsContentUtils::IsCallerChrome()) {
     return NS_ERROR_DOM_SECURITY_ERR;
   }
 
   // get the widget to send the event to
   nsPoint offset;
   nsCOMPtr<nsIWidget> widget = GetWidget(&offset);
@@ -579,19 +577,17 @@ nsDOMWindowUtils::SendMouseEventCommon(c
     msg = NS_MOUSE_MOVE;
   else if (aType.EqualsLiteral("mouseover"))
     msg = NS_MOUSE_ENTER;
   else if (aType.EqualsLiteral("mouseout"))
     msg = NS_MOUSE_EXIT;
   else if (aType.EqualsLiteral("contextmenu")) {
     msg = NS_CONTEXTMENU;
     contextMenuKey = (aButton == 0);
-  } else if (aType.EqualsLiteral("MozMouseHittest"))
-    msg = NS_MOUSE_MOZHITTEST;
-  else
+  } else
     return NS_ERROR_FAILURE;
 
   if (aInputSourceArg == nsIDOMMouseEvent::MOZ_SOURCE_UNKNOWN) {
     aInputSourceArg = nsIDOMMouseEvent::MOZ_SOURCE_MOUSE;
   }
 
   nsMouseEvent event(true, msg, widget, nsMouseEvent::eReal,
                      contextMenuKey ?
@@ -622,20 +618,17 @@ nsDOMWindowUtils::SendMouseEventCommon(c
       return NS_ERROR_FAILURE;
     nsIView* view = viewManager->GetRootView();
     if (!view)
       return NS_ERROR_FAILURE;
 
     status = nsEventStatus_eIgnore;
     return presShell->HandleEvent(view->GetFrame(), &event, false, &status);
   }
-  nsresult rv = widget->DispatchEvent(&event, status);
-  *aPreventDefault = (status == nsEventStatus_eConsumeNoDefault);
-
-  return rv;
+  return widget->DispatchEvent(&event, status);
 }
 
 NS_IMETHODIMP
 nsDOMWindowUtils::SendWheelEvent(float aX,
                                  float aY,
                                  double aDeltaX,
                                  double aDeltaY,
                                  double aDeltaZ,

--- a/dom/base/nsDOMWindowUtils.h
+++ b/dom/base/nsDOMWindowUtils.h
@@ -39,13 +39,12 @@ protected:
                                   float aX,
                                   float aY,
                                   int32_t aButton,
                                   int32_t aClickCount,
                                   int32_t aModifiers,
                                   bool aIgnoreRootScrollFrame,
                                   float aPressure,
                                   unsigned short aInputSourceArg,
-                                  bool aToWindow,
-                                  bool *aPreventDefault);
+                                  bool aToWindow);
 
   static mozilla::widget::Modifiers GetWidgetModifiers(int32_t aModifiers);
 };

--- a/dom/interfaces/base/nsIDOMWindowUtils.idl
+++ b/dom/interfaces/base/nsIDOMWindowUtils.idl
@@ -35,17 +35,17 @@ interface nsIQueryContentEventResult;
 interface nsIDOMWindow;
 interface nsIDOMBlob;
 interface nsIDOMFile;
 interface nsIFile;
 interface nsIDOMTouch;
 interface nsIDOMClientRect;
 interface nsIURI;
 
-[scriptable, uuid(b3a3589d-cc9d-4123-9b21-51c66e88b436)]
+[scriptable, uuid(C98B7275-93C4-4EAD-B7CF-573D872C1071)]
 interface nsIDOMWindowUtils : nsISupports {
 
   /**
    * Image animation mode of the window. When this attribute's value
    * is changed, the implementation should set all images in the window
    * to the given value. That is, when set to kDontAnimMode, all images
    * will stop animating. The attribute's value must be one of the
    * animationMode values from imgIContainer.
@@ -199,18 +199,17 @@ interface nsIDOMWindowUtils : nsISupport
   const long MODIFIER_CAPSLOCK   = 0x0020;
   const long MODIFIER_FN         = 0x0040;
   const long MODIFIER_NUMLOCK    = 0x0080;
   const long MODIFIER_SCROLLLOCK = 0x0100;
   const long MODIFIER_SYMBOLLOCK = 0x0200;
   const long MODIFIER_OS         = 0x0400;
 
   /** Synthesize a mouse event. The event types supported are:
-   *    mousedown, mouseup, mousemove, mouseover, mouseout, contextmenu,
-   *    MozMouseHitTest
+   *    mousedown, mouseup, mousemove, mouseover, mouseout, contextmenu
    *
    * Events are sent in coordinates offset by aX and aY from the window.
    *
    * Note that additional events may be fired as a result of this call. For
    * instance, typically a click event will be fired as a result of a
    * mousedown and mouseup in sequence.
    *
    * Normally at this level of events, the mouseover and mouseout events are
@@ -232,28 +231,26 @@ interface nsIDOMWindowUtils : nsISupport
    * @param aButton button to synthesize
    * @param aClickCount number of clicks that have been performed
    * @param aModifiers modifiers pressed, using constants defined as MODIFIER_*
    * @param aIgnoreRootScrollFrame whether the event should ignore viewport bounds
    *                           during dispatch
    * @param aPressure touch input pressure: 0.0 -> 1.0
    * @param aInputSourceArg input source, see nsIDOMMouseEvent for values,
    *        defaults to mouse input.
-   *
-   * returns true if the page called prevent default on this event
    */
-  boolean sendMouseEvent(in AString aType,
-                         in float aX,
-                         in float aY,
-                         in long aButton,
-                         in long aClickCount,
-                         in long aModifiers,
-                         [optional] in boolean aIgnoreRootScrollFrame,
-                         [optional] in float aPressure,
-                         [optional] in unsigned short aInputSourceArg);
+  void sendMouseEvent(in AString aType,
+                      in float aX,
+                      in float aY,
+                      in long aButton,
+                      in long aClickCount,
+                      in long aModifiers,
+                      [optional] in boolean aIgnoreRootScrollFrame,
+                      [optional] in float aPressure,
+                      [optional] in unsigned short aInputSourceArg);
 
   /** Synthesize a touch event. The event types supported are:
    *    touchstart, touchend, touchmove, and touchcancel
    *
    * Events are sent in coordinates offset by aX and aY from the window.
    *
    * Cannot be accessed from unprivileged context (not content-accessible)
    * Will throw a DOM security error if called without UniversalXPConnect

--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -1271,19 +1271,18 @@ TabChild::RecvMouseEvent(const nsString&
                          const float&    aY,
                          const int32_t&  aButton,
                          const int32_t&  aClickCount,
                          const int32_t&  aModifiers,
                          const bool&     aIgnoreRootScrollFrame)
 {
   nsCOMPtr<nsIDOMWindowUtils> utils(GetDOMWindowUtils());
   NS_ENSURE_TRUE(utils, true);
-  bool ignored = false;
   utils->SendMouseEvent(aType, aX, aY, aButton, aClickCount, aModifiers,
-                        aIgnoreRootScrollFrame, 0, 0, &ignored);
+                        aIgnoreRootScrollFrame, 0, 0);
   return true;
 }
 
 bool
 TabChild::RecvRealMouseEvent(const nsMouseEvent& event)
 {
   nsMouseEvent localEvent(event);
   DispatchWidgetEvent(localEvent);

--- a/testing/mochitest/tests/SimpleTest/EventUtils.js
+++ b/testing/mochitest/tests/SimpleTest/EventUtils.js
@@ -201,23 +201,21 @@ function _parseModifiers(aEvent)
  *
  * aEvent is an object which may contain the properties:
  *   shiftKey, ctrlKey, altKey, metaKey, accessKey, clickCount, button, type
  *
  * If the type is specified, an mouse event of that type is fired. Otherwise,
  * a mousedown followed by a mouse up is performed.
  *
  * aWindow is optional, and defaults to the current window object.
- *
- * Returns whether the event had preventDefault() called on it.
  */
 function synthesizeMouse(aTarget, aOffsetX, aOffsetY, aEvent, aWindow)
 {
   var rect = aTarget.getBoundingClientRect();
-  return synthesizeMouseAtPoint(rect.left + aOffsetX, rect.top + aOffsetY,
+  synthesizeMouseAtPoint(rect.left + aOffsetX, rect.top + aOffsetY,
        aEvent, aWindow);
 }
 function synthesizeTouch(aTarget, aOffsetX, aOffsetY, aEvent, aWindow)
 {
   var rect = aTarget.getBoundingClientRect();
   synthesizeTouchAtPoint(rect.left + aOffsetX, rect.top + aOffsetY,
        aEvent, aWindow);
 }
@@ -231,33 +229,30 @@ function synthesizeTouch(aTarget, aOffse
  * If the type is specified, an mouse event of that type is fired. Otherwise,
  * a mousedown followed by a mouse up is performed.
  *
  * aWindow is optional, and defaults to the current window object.
  */
 function synthesizeMouseAtPoint(left, top, aEvent, aWindow)
 {
   var utils = _getDOMWindowUtils(aWindow);
-  var defaultPrevented = false;
 
   if (utils) {
     var button = aEvent.button || 0;
     var clickCount = aEvent.clickCount || 1;
     var modifiers = _parseModifiers(aEvent);
 
     if (("type" in aEvent) && aEvent.type) {
-      defaultPrevented = utils.sendMouseEvent(aEvent.type, left, top, button, clickCount, modifiers);
+      utils.sendMouseEvent(aEvent.type, left, top, button, clickCount, modifiers);
     }
     else {
       utils.sendMouseEvent("mousedown", left, top, button, clickCount, modifiers);
       utils.sendMouseEvent("mouseup", left, top, button, clickCount, modifiers);
     }
   }
-
-  return defaultPrevented;
 }
 function synthesizeTouchAtPoint(left, top, aEvent, aWindow)
 {
   var utils = _getDOMWindowUtils(aWindow);
 
   if (utils) {
     var id = aEvent.id || 0;
     var rx = aEvent.rx || 1;

--- a/toolkit/content/WindowDraggingUtils.jsm
+++ b/toolkit/content/WindowDraggingUtils.jsm
@@ -1,24 +1,18 @@
 /* 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/. */
 
-#ifdef XP_WIN
-#define USE_HITTEST
-#elifdef MOZ_WIDGET_COCOA
-#define USE_HITTEST
-#endif
-
 this.EXPORTED_SYMBOLS = [ "WindowDraggingElement" ];
 
 this.WindowDraggingElement = function WindowDraggingElement(elem) {
   this._elem = elem;
   this._window = elem.ownerDocument.defaultView;
-#ifdef USE_HITTEST
+#ifdef XP_WIN
   if (!this.isPanel())
     this._elem.addEventListener("MozMouseHittest", this, false);
   else
 #endif
   this._elem.addEventListener("mousedown", this, false);
 };
 
 WindowDraggingElement.prototype = {
@@ -55,17 +49,17 @@ WindowDraggingElement.prototype = {
     return true;
   },
   isPanel : function() {
     return this._elem instanceof Components.interfaces.nsIDOMXULElement &&
            this._elem.localName == "panel";
   },
   handleEvent: function(aEvent) {
     let isPanel = this.isPanel();
-#ifdef USE_HITTEST
+#ifdef XP_WIN
     if (!isPanel) {
       if (this.shouldDrag(aEvent))
         aEvent.preventDefault();
       return;
     }
 #endif
 
     switch (aEvent.type) {

--- a/toolkit/content/tests/chrome/window_titlebar.xul
+++ b/toolkit/content/tests/chrome/window_titlebar.xul
@@ -47,16 +47,17 @@
       <label id="panellabelfloating" value="Titlebar"/>
     </titlebar>
   </panel>
 
   <button id="button" label="OK"/>
   <statusbar id="statusbar">
     <statusbarpanel>
       <label id="statuslabel" value="Status"/>
+      <label id="statuslabelnodrag" value="No Drag" onmousedown="event.preventDefault()"/>
     </statusbarpanel>
   </statusbar>
 
 <script>
 <![CDATA[
 
 var SimpleTest = window.opener.wrappedJSObject.SimpleTest;
 
@@ -100,28 +101,36 @@ function waitForWindowMove(element, x, y
   }
 }
 
 function test_titlebar()
 {
   var titlebar = document.getElementById("titlebar");
   var label = document.getElementById("label");
 
-  // On Mac, the window can also be moved with the statusbar, but this works
-  // via the MozMouseHittest event, not via mouse events.
+  // on Mac, the window can also be moved with the statusbar
   if (navigator.platform.indexOf("Mac") >= 0) {
-    var preventDefaulted;
-
     var statuslabel = document.getElementById("statuslabel");
-    preventDefaulted = synthesizeMouse(statuslabel, 2, 2, { type: "MozMouseHittest" });
-    SimpleTest.ok(preventDefaulted, "MozMouseHittest should have been defaultPrevented over statusbar");
+    var statuslabelnodrag = document.getElementById("statuslabelnodrag");
+
+    origoldx = window.screenX;
+    origoldy = window.screenY;
 
-    var button = document.getElementById("button");
-    preventDefaulted = synthesizeMouse(button, 2, 2, { type: "MozMouseHittest" });
-    SimpleTest.ok(!preventDefaulted, "MozMouseHittest should NOT have been defaultPrevented over button");
+    synthesizeMouse(statuslabel, 2, 2, { type: "mousedown" });
+    synthesizeMouse(statuslabel, 22, 22, { type: "mousemove" });
+    SimpleTest.is(window.screenX, origoldx + 20, "move window with statusbar horizontal");
+    SimpleTest.is(window.screenY, origoldy + 20, "move window with statusbar vertical");
+    synthesizeMouse(statuslabel, 22, 22, { type: "mouseup" });
+
+    // event was cancelled so the drag should not have occurred
+    synthesizeMouse(statuslabelnodrag, 2, 2, { type: "mousedown" });
+    synthesizeMouse(statuslabelnodrag, 22, 22, { type: "mousemove" });
+    SimpleTest.is(window.screenX, origoldx + 20, "move window with statusbar cancelled mousedown horizontal");
+    SimpleTest.is(window.screenY, origoldy + 20, "move window with statusbar cancelled mousedown vertical");
+    synthesizeMouse(statuslabelnodrag, 22, 22, { type: "mouseup" });
   }
 
   origoldx = window.screenX;
   origoldy = window.screenY;
 
   var mousedownListener = function (event) mouseDownTarget = event.originalTarget;
   window.addEventListener("mousedown", mousedownListener, false);
   synthesizeMouse(label, 2, 2, { type: "mousedown" });

--- a/widget/cocoa/nsChildView.h
+++ b/widget/cocoa/nsChildView.h
@@ -178,20 +178,16 @@ typedef NSInteger NSEventGestureAxis;
 // automatically firing momentum scroll events.
 @interface NSEvent (ScrollPhase)
 // Leopard and SnowLeopard
 - (long long)_scrollPhase;
 // Lion and above
 - (NSEventPhase)momentumPhase;
 @end
 
-@protocol EventRedirection
-  - (NSView*)targetView;
-@end
-
 @interface ChildView : NSView<
 #ifdef ACCESSIBILITY
                               mozAccessible,
 #endif
                               mozView, NSTextInput>
 {
 @private
   // the nsChildView that created the view. It retains this NSView, so
@@ -266,29 +262,25 @@ typedef NSInteger NSEventGestureAxis;
 
   // Whether this uses off-main-thread compositing.
   BOOL mUsingOMTCompositor;
 }
 
 // class initialization
 + (void)initialize;
 
-+ (void)registerViewForDraggedTypes:(NSView*)aView;
-
 // these are sent to the first responder when the window key status changes
 - (void)viewsWindowDidBecomeKey;
 - (void)viewsWindowDidResignKey;
 
 // Stop NSView hierarchy being changed during [ChildView drawRect:]
 - (void)delayedTearDown;
 
 - (void)sendFocusEvent:(uint32_t)eventType;
 
-- (void)updateWindowDraggableStateOnMouseMove:(NSEvent*)theEvent;
-
 - (void)handleMouseMoved:(NSEvent*)aEvent;
 
 - (void)drawRect:(NSRect)aRect inTitlebarContext:(CGContextRef)aContext;
 
 - (void)sendMouseEnterOrExitEvent:(NSEvent*)aEvent
                             enter:(BOOL)aEnter
                              type:(nsMouseEvent::exitType)aType;
 

--- a/widget/cocoa/nsChildView.mm
+++ b/widget/cocoa/nsChildView.mm
@@ -1907,30 +1907,16 @@ NSEvent* gLastDragMouseDownEvent = nil;
 
     [sendTypes release];
     [returnTypes release];
 
     initialized = YES;
   }
 }
 
-+ (void)registerViewForDraggedTypes:(NSView*)aView
-{
-  [aView registerForDraggedTypes:[NSArray arrayWithObjects:NSFilenamesPboardType,
-                                                           NSStringPboardType,
-                                                           NSHTMLPboardType,
-                                                           NSURLPboardType,
-                                                           NSFilesPromisePboardType,
-                                                           kWildcardPboardType,
-                                                           kCorePboardType_url,
-                                                           kCorePboardType_urld,
-                                                           kCorePboardType_urln,
-                                                           nil]];
-}
-
 // initWithFrame:geckoChild:
 - (id)initWithFrame:(NSRect)inFrame geckoChild:(nsChildView*)inChild
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;
 
   if ((self = [super initWithFrame:inFrame])) {
     mGeckoChild = inChild;
     mIsPluginView = NO;
@@ -1968,18 +1954,27 @@ NSEvent* gLastDragMouseDownEvent = nil;
     [self setFocusRingType:NSFocusRingTypeNone];
 
 #ifdef __LP64__
     mSwipeAnimationCancelled = nil;
 #endif
   }
   
   // register for things we'll take from other applications
-  [ChildView registerViewForDraggedTypes:self];
-
+  PR_LOG(sCocoaLog, PR_LOG_ALWAYS, ("ChildView initWithFrame: registering drag types\n"));
+  [self registerForDraggedTypes:[NSArray arrayWithObjects:NSFilenamesPboardType,
+                                                          NSStringPboardType,
+                                                          NSHTMLPboardType,
+                                                          NSURLPboardType,
+                                                          NSFilesPromisePboardType,
+                                                          kWildcardPboardType,
+                                                          kCorePboardType_url,
+                                                          kCorePboardType_urld,
+                                                          kCorePboardType_urln,
+                                                          nil]];
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(windowBecameMain:)
                                                name:NSWindowDidBecomeMainNotification
                                              object:nil];
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(windowResignedMain:)
                                                name:NSWindowDidResignMainNotification
                                              object:nil];
@@ -2339,17 +2334,17 @@ NSEvent* gLastDragMouseDownEvent = nil;
   }
   [super scrollRect:aRect by:offset];
 
   NS_OBJC_END_TRY_ABORT_BLOCK;
 }
 
 - (BOOL)mouseDownCanMoveWindow
 {
-  return [[self window] isMovableByWindowBackground];
+  return NO;
 }
 
 - (void)lockFocus
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   [super lockFocus];
 
@@ -3285,35 +3280,16 @@ NSEvent* gLastDragMouseDownEvent = nil;
   }
 
   event.exit = aType;
 
   nsEventStatus status; // ignored
   mGeckoChild->DispatchEvent(&event, status);
 }
 
-- (void)updateWindowDraggableStateOnMouseMove:(NSEvent*)theEvent
-{
-  if (!theEvent || !mGeckoChild) {
-    return;
-  }
-
-  nsCocoaWindow* windowWidget = mGeckoChild->GetXULWindowWidget();
-  if (!windowWidget) {
-    return;
-  }
-
-  // We assume later on that sending a hit test event won't cause widget destruction.
-  nsMouseEvent hitTestEvent(true, NS_MOUSE_MOZHITTEST, mGeckoChild, nsMouseEvent::eReal);
-  [self convertCocoaMouseEvent:theEvent toGeckoEvent:&hitTestEvent];
-  bool result = mGeckoChild->DispatchWindowEvent(hitTestEvent);
-
-  [windowWidget->GetCocoaWindow() setMovableByWindowBackground:result];
-}
-
 - (void)handleMouseMoved:(NSEvent*)theEvent
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   if (!mGeckoChild)
     return;
 
   nsMouseEvent geckoEvent(true, NS_MOUSE_MOVE, mGeckoChild, nsMouseEvent::eReal);
@@ -4828,21 +4804,16 @@ ChildView*
 ChildViewMouseTracker::ViewForEvent(NSEvent* aEvent)
 {
   NSWindow* window = sWindowUnderMouse;
   if (!window)
     return nil;
 
   NSPoint windowEventLocation = nsCocoaUtils::EventLocationForWindow(aEvent, window);
   NSView* view = [[[window contentView] superview] hitTest:windowEventLocation];
-
-  while([view conformsToProtocol:@protocol(EventRedirection)]) {
-    view = [(id<EventRedirection>)view targetView];
-  }
-
   if (![view isKindOfClass:[ChildView class]])
     return nil;
 
   ChildView* childView = (ChildView*)view;
   // If childView is being destroyed return nil.
   if (![childView widget])
     return nil;
   return WindowAcceptsEvent(window, aEvent, childView) ? childView : nil;
@@ -4931,17 +4902,17 @@ ChildViewMouseTracker::WindowAcceptsEven
 // triggers bmo bugs 431902 and 476393.  So here we make sure that a
 // ToolbarWindow's contentView always returns NO from the
 // mouseDownCanMoveWindow method.
 - (BOOL)nsChildView_NSView_mouseDownCanMoveWindow
 {
   NSWindow *ourWindow = [self window];
   NSView *contentView = [ourWindow contentView];
   if ([ourWindow isKindOfClass:[ToolbarWindow class]] && (self == contentView))
-    return [ourWindow isMovableByWindowBackground];
+    return NO;
   return [self nsChildView_NSView_mouseDownCanMoveWindow];
 }
 
 @end
 
 #ifdef __LP64__
 // When using blocks, at least on OS X 10.7, the OS sometimes calls
 // +[NSEvent removeMonitor:] more than once on a single event monitor, which

--- a/widget/cocoa/nsCocoaWindow.h
+++ b/widget/cocoa/nsCocoaWindow.h
@@ -13,17 +13,16 @@
 #include "nsBaseWidget.h"
 #include "nsPIWidgetCocoa.h"
 #include "nsAutoPtr.h"
 #include "nsCocoaUtils.h"
 
 class nsCocoaWindow;
 class nsChildView;
 class nsMenuBarX;
-@class ChildView;
 
 // Value copied from BITMAP_MAX_AREA, used in nsNativeThemeCocoa.mm
 #define CUIDRAW_MAX_AREA 500000
 
 // If we are using an SDK older than 10.7, define bits we need that are missing
 // from it.
 #if !defined(MAC_OS_X_VERSION_10_7) || \
     MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
@@ -172,28 +171,26 @@ typedef struct _nsCocoaWindowList {
 @end
 
 // NSWindow subclass for handling windows with toolbars.
 @interface ToolbarWindow : BaseWindow
 {
   TitlebarAndBackgroundColor *mColor;
   float mUnifiedToolbarHeight;
   NSColor *mBackgroundColor;
-  NSView *mTitlebarView; // strong
 }
 // Pass nil here to get the default appearance.
 - (void)setTitlebarColor:(NSColor*)aColor forActiveWindow:(BOOL)aActive;
 - (void)setUnifiedToolbarHeight:(float)aHeight;
 - (float)unifiedToolbarHeight;
 - (float)titlebarHeight;
 - (NSRect)titlebarRect;
 - (void)setTitlebarNeedsDisplayInRect:(NSRect)aRect sync:(BOOL)aSync;
 - (void)setTitlebarNeedsDisplayInRect:(NSRect)aRect;
 - (void)setDrawsContentsIntoWindowFrame:(BOOL)aState;
-- (ChildView*)mainChildView;
 @end
 
 class nsCocoaWindow : public nsBaseWidget, public nsPIWidgetCocoa
 {
 private:
   
   typedef nsBaseWidget Inherited;
 

--- a/widget/cocoa/nsCocoaWindow.mm
+++ b/widget/cocoa/nsCocoaWindow.mm
@@ -442,20 +442,16 @@ nsresult nsCocoaWindow::CreateNativeWind
     [mWindow setHasShadow:YES];
   }
 
   [mWindow setBackgroundColor:[NSColor clearColor]];
   [mWindow setOpaque:NO];
   [mWindow setContentMinSize:NSMakeSize(60, 60)];
   [mWindow disableCursorRects];
 
-  // Make sure the window starts out not draggable by the background.
-  // We will turn it on as necessary.
-  [mWindow setMovableByWindowBackground:NO];
-
   [[WindowDataMap sharedWindowDataMap] ensureDataForWindow:mWindow];
   mWindowMadeHere = true;
 
   return NS_OK;
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }
 
@@ -2582,104 +2578,17 @@ static const NSString* kStateShowsToolba
     retval = [NSArray arrayWithArray:holder];
   }
 
   return retval;
 }
 
 @end
 
-@interface TitlebarMouseHandlingView : NSView<EventRedirection>
-{
-  ToolbarWindow* mWindow; // weak
-  BOOL mProcessingRightMouseDown;
-}
-
-- (id)initWithWindow:(ToolbarWindow*)aWindow;
-@end
-
-@implementation TitlebarMouseHandlingView
-
-- (id)initWithWindow:(ToolbarWindow*)aWindow
-{
-  if ((self = [super initWithFrame:[aWindow titlebarRect]])) {
-    mWindow = aWindow;
-    [self setAutoresizingMask:(NSViewWidthSizable | NSViewMinYMargin)];
-    [ChildView registerViewForDraggedTypes:self];
-    mProcessingRightMouseDown = NO;
-  }
-  return self;
-}
-
-- (NSView*)targetView
-{
-  return [mWindow mainChildView];
-}
-
-- (BOOL)mouseDownCanMoveWindow
-{
-  return [mWindow isMovableByWindowBackground];
-}
-
-// We redirect many types of events to the window's mainChildView simply by
-// passing the event object to the respective handler method. We don't need any
-// coordinate transformations because event coordinates are relative to the
-// window.
-// We only need to handle event types whose target NSView is determined by the
-// event's position. We don't need to handle key events and NSMouseMoved events
-// because those are only sent to the window's first responder. This view
-// doesn't override acceptsFirstResponder, so it will never receive those kinds
-// of events.
-
-- (void)mouseMoved:(NSEvent*)aEvent            { [[self targetView] mouseMoved:aEvent]; }
-- (void)mouseDown:(NSEvent*)aEvent             { [[self targetView] mouseDown:aEvent]; }
-- (void)mouseUp:(NSEvent*)aEvent               { [[self targetView] mouseUp:aEvent]; }
-- (void)mouseDragged:(NSEvent*)aEvent          { [[self targetView] mouseDragged:aEvent]; }
-- (void)rightMouseDown:(NSEvent*)aEvent
-{
-  // To avoid recursion...
-  if (mProcessingRightMouseDown)
-    return;
-  mProcessingRightMouseDown = YES;
-  [[self targetView] rightMouseDown:aEvent];
-  mProcessingRightMouseDown = NO;
-}
-- (void)rightMouseUp:(NSEvent*)aEvent          { [[self targetView] rightMouseUp:aEvent]; }
-- (void)rightMouseDragged:(NSEvent*)aEvent     { [[self targetView] rightMouseDragged:aEvent]; }
-- (void)otherMouseDown:(NSEvent*)aEvent        { [[self targetView] otherMouseDown:aEvent]; }
-- (void)otherMouseUp:(NSEvent*)aEvent          { [[self targetView] otherMouseUp:aEvent]; }
-- (void)otherMouseDragged:(NSEvent*)aEvent     { [[self targetView] otherMouseDragged:aEvent]; }
-- (void)scrollWheel:(NSEvent*)aEvent           { [[self targetView] scrollWheel:aEvent]; }
-- (void)swipeWithEvent:(NSEvent*)aEvent        { [[self targetView] swipeWithEvent:aEvent]; }
-- (void)beginGestureWithEvent:(NSEvent*)aEvent { [[self targetView] beginGestureWithEvent:aEvent]; }
-- (void)magnifyWithEvent:(NSEvent*)aEvent      { [[self targetView] magnifyWithEvent:aEvent]; }
-- (void)rotateWithEvent:(NSEvent*)aEvent       { [[self targetView] rotateWithEvent:aEvent]; }
-- (void)endGestureWithEvent:(NSEvent*)aEvent   { [[self targetView] endGestureWithEvent:aEvent]; }
-- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender
-  { return [[self targetView] draggingEntered:sender]; }
-- (NSDragOperation)draggingUpdated:(id <NSDraggingInfo>)sender
-  { return [[self targetView] draggingUpdated:sender]; }
-- (void)draggingExited:(id <NSDraggingInfo>)sender
-  { [[self targetView] draggingExited:sender]; }
-- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
-  { return [[self targetView] performDragOperation:sender]; }
-- (void)draggedImage:(NSImage *)anImage endedAt:(NSPoint)aPoint operation:(NSDragOperation)operation
-  { [[self targetView] draggedImage:anImage endedAt:aPoint operation:operation]; }
-- (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal
-  { return [[self targetView] draggingSourceOperationMaskForLocal:isLocal]; }
-- (NSArray *)namesOfPromisedFilesDroppedAtDestination:(NSURL*)dropDestination
-  { return [[self targetView] namesOfPromisedFilesDroppedAtDestination:dropDestination]; }
-- (NSMenu*)menuForEvent:(NSEvent*)aEvent
-  { return [[self targetView] menuForEvent:aEvent]; }
-
-@end
-
-// This class allows us to exercise control over the window's title bar. This
-// allows for a "unified toolbar" look, and for extending the content area into
-// the title bar. It works like this:
+// This class allows us to have a "unified toolbar" style window. It works like this:
 // 1) We set the window's style to textured.
 // 2) Because of this, the background color applies to the entire window, including
 //     the titlebar area. For normal textured windows, the default pattern is a 
 //    "brushed metal" image on Tiger and a unified gradient on Leopard.
 // 3) We set the background color to a custom NSColor subclass that knows how tall the window is.
 //    When -set is called on it, it sets a pattern (with a draw callback) as the fill. In that callback,
 //    it paints the the titlebar and background colors in the correct areas of the context it's given,
 //    which will fill the entire window (CG will tile it horizontally for us).
@@ -2703,21 +2612,16 @@ static const NSString* kStateShowsToolba
 //
 // Whenever the unified gradient is drawn in the titlebar or the toolbar, both
 // titlebar height and toolbar height must be known in order to construct the
 // correct gradient (which is a linear gradient with the length
 // titlebarHeight + toolbarHeight - 1). But you can only get from the toolbar frame
 // to the containing window - the other direction doesn't work. That's why the
 // toolbar height is cached in the ToolbarWindow but nsNativeThemeCocoa can simply
 // query the window for its titlebar height when drawing the toolbar.
-@interface ToolbarWindow(Private)
-- (void)installTitlebarMouseHandlingView;
-- (void)uninstallTitlebarMouseHandlingView;
-@end;
-
 @implementation ToolbarWindow
 
 - (id)initWithContentRect:(NSRect)aContentRect styleMask:(NSUInteger)aStyle backing:(NSBackingStoreType)aBufferingType defer:(BOOL)aFlag
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;
 
   aStyle = aStyle | NSTexturedBackgroundWindowMask;
   if ((self = [super initWithContentRect:aContentRect styleMask:aStyle backing:aBufferingType defer:aFlag])) {
@@ -2742,17 +2646,16 @@ static const NSString* kStateShowsToolba
 }
 
 - (void)dealloc
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   [mColor release];
   [mBackgroundColor release];
-  [mTitlebarView release];
   [super dealloc];
 
   NS_OBJC_END_TRY_ABORT_BLOCK;
 }
 
 - (void)setTitlebarColor:(NSColor*)aColor forActiveWindow:(BOOL)aActive
 {
   [super setTitlebarColor:aColor forActiveWindow:aActive];
@@ -2822,101 +2725,39 @@ static const NSString* kStateShowsToolba
   [self setContentBorderThickness:mUnifiedToolbarHeight forEdge:NSMaxYEdge];
 
   // Redraw the title bar. If we're inside painting, we'll do it right now,
   // otherwise we'll just invalidate it.
   BOOL needSyncRedraw = ([NSView focusView] != nil);
   [self setTitlebarNeedsDisplayInRect:[self titlebarRect] sync:needSyncRedraw];
 }
 
-// Extending the content area into the title bar works by redirection of both
-// drawing and mouse events.
-// The window's NSView hierarchy looks like this:
-//  - border view ([[window contentView] superview])
-//     - transparent title bar event redirection view
-//     - window controls (traffic light buttons)
-//     - content view ([window contentView], default NSView provided by the window)
-//        - our main Gecko ChildView ([window mainChildView]), which has an
-//          OpenGL context attached to it when accelerated
-//           - possibly more ChildViews for plugins
-//
-// When the window is in title bar extension mode, the mainChildView covers the
-// whole window but is only visible in the content area of the window, because
-// it's a subview of the window's contentView and thus clipped to its dimensions.
-// This clipping is a good thing because it avoids a few problems. For example,
-// if the mainChildView weren't clipped and thus visible in the titlebar, we'd
-// have have to do the rounded corner masking and the drawing of the highlight
-// line ourselves.
-// This would be especially hard in combination with OpenGL acceleration since
-// rounded corners would require making the OpenGL context transparent, which
-// would bring another set of challenges with it. Having the window controls
-// draw on top of an OpenGL context could be hard, too.
-//
-// So title bar drawing happens in the border view. The border view's drawRect
-// method is not under our control, but we can get it to call into our code
-// using some tricks, see the TitlebarAndBackgroundColor class below.
-// Specifically, we have it call the TitlebarDrawCallback function, which
-// draws the contents of mainChildView into the provided CGContext.
-// (Even if the ChildView uses OpenGL for rendering, drawing in the title bar
-// will happen non-accelerated in that CGContext.)
-//
-// Mouse event redirection happens via a TitlebarMouseHandlingView which we
-// install below.
 - (void)setDrawsContentsIntoWindowFrame:(BOOL)aState
 {
   BOOL stateChanged = ([self drawsContentsIntoWindowFrame] != aState);
   [super setDrawsContentsIntoWindowFrame:aState];
   if (stateChanged && [[self delegate] isKindOfClass:[WindowDelegate class]]) {
-    // Here we extend / shrink our mainChildView. We do that by firing a resize
-    // event which will cause the ChildView to be resized to the rect returned
-    // by nsCocoaWindow::GetClientBounds. GetClientBounds bases its return
-    // value on what we return from drawsContentsIntoWindowFrame.
     WindowDelegate *windowDelegate = (WindowDelegate *)[self delegate];
     nsCocoaWindow *geckoWindow = [windowDelegate geckoWidget];
     if (geckoWindow) {
       // Re-layout our contents.
       geckoWindow->ReportSizeEvent();
     }
 
     // Resizing the content area causes a reflow which would send a synthesized
     // mousemove event to the old mouse position relative to the top left
     // corner of the content area. But the mouse has shifted relative to the
     // content area, so that event would have wrong position information. So
     // we'll send a mouse move event with the correct new position.
     ChildViewMouseTracker::ResendLastMouseMoveEvent();
 
-    if (aState) {
-      [self installTitlebarMouseHandlingView];
-    } else {
-      [self uninstallTitlebarMouseHandlingView];
-    }
+    [self setTitlebarNeedsDisplayInRect:[self titlebarRect]];
   }
 }
 
-- (void)installTitlebarMouseHandlingView
-{
-  mTitlebarView = [[TitlebarMouseHandlingView alloc] initWithWindow:self];
-  [[[self contentView] superview] addSubview:mTitlebarView positioned:NSWindowBelow relativeTo:nil];
-}
-
-- (void)uninstallTitlebarMouseHandlingView
-{
-  [mTitlebarView removeFromSuperview];
-  [mTitlebarView release];
-  mTitlebarView = nil;
-}
-
-- (ChildView*)mainChildView
-{
-  NSView* view = [[[self contentView] subviews] lastObject];
-  if (view && [view isKindOfClass:[ChildView class]])
-    return (ChildView*)view;
-  return nil;
-}
-
 // Returning YES here makes the setShowsToolbarButton method work even though
 // the window doesn't contain an NSToolbar.
 - (BOOL)_hasToolbar
 {
   return YES;
 }
 
 // Dispatch a toolbar pill button clicked message to Gecko.
@@ -2975,19 +2816,16 @@ static const NSString* kStateShowsToolba
     {
       // Drop all mouse events if a modal window has appeared above us.
       // This helps make us behave as if the OS were running a "real" modal
       // event loop.
       id delegate = [self delegate];
       if (delegate && [delegate isKindOfClass:[WindowDelegate class]]) {
         nsCocoaWindow *widget = [(WindowDelegate *)delegate geckoWidget];
         if (widget) {
-          if (type == NSMouseMoved) {
-            [[self mainChildView] updateWindowDraggableStateOnMouseMove:anEvent];
-          }
           if (gGeckoAppModalWindowList && (widget != gGeckoAppModalWindowList->window))
             return;
           if (widget->HasModalDescendents())
             return;
         }
       }
       break;
     }
@@ -3043,29 +2881,29 @@ DrawNativeTitlebar(CGContextRef aContext
 // Pattern draw callback for standard titlebar gradients and solid titlebar colors
 static void
 TitlebarDrawCallback(void* aInfo, CGContextRef aContext)
 {
   ToolbarWindow *window = (ToolbarWindow*)aInfo;
   NSRect titlebarRect = [window titlebarRect];
 
   if ([window drawsContentsIntoWindowFrame]) {
-    ChildView* view = [window mainChildView];
-    if (!view)
+    NSView* view = [[[window contentView] subviews] lastObject];
+    if (!view || ![view isKindOfClass:[ChildView class]])
       return;
 
     // Gecko drawing assumes flippedness, but the current context isn't flipped
     // (because we're painting into the window's border view, which is not a
     // ChildView, so it isn't flipped).
     // So we need to set a flip transform.
     CGContextScaleCTM(aContext, 1.0f, -1.0f);
     CGContextTranslateCTM(aContext, 0.0f, -[window frame].size.height);
 
     NSRect flippedTitlebarRect = { NSZeroPoint, titlebarRect.size };
-    [view drawRect:flippedTitlebarRect inTitlebarContext:aContext];
+    [(ChildView*)view drawRect:flippedTitlebarRect inTitlebarContext:aContext];
   } else {
     BOOL isMain = [window isMainWindow];
     NSColor *titlebarColor = [window titlebarColorForActiveWindow:isMain];
     if (!titlebarColor) {
       // If the titlebar color is nil, draw the default titlebar shading.
       DrawNativeTitlebar(aContext, NSRectToCGRect(titlebarRect),
                          [window unifiedToolbarHeight], isMain);
     } else {