--- a/gfx/layers/ipc/ShadowLayers.cpp
+++ b/gfx/layers/ipc/ShadowLayers.cpp
@@ -508,17 +508,17 @@ ShadowLayerForwarder::StorePluginWidgetC
 {
   // Cache new plugin widget configs here until we call update, at which
   // point this data will get shipped over to chrome.
   mPluginWindowData.Clear();
   for (uint32_t idx = 0; idx < aConfigurations.Length(); idx++) {
     const nsIWidget::Configuration& configuration = aConfigurations[idx];
     mPluginWindowData.AppendElement(PluginWindowData(configuration.mWindowID,
                                                      configuration.mClipRegion,
-                                                     configuration.mBounds,
+                                                     configuration.mBounds.ToUnknownRect(),
                                                      configuration.mVisible));
   }
 }
 
 bool
 ShadowLayerForwarder::EndTransaction(InfallibleTArray<EditReply>* aReplies,
                                      const nsIntRegion& aRegionToClear,
                                      uint64_t aId,

--- a/layout/base/nsPresContext.cpp
+++ b/layout/base/nsPresContext.cpp
@@ -3127,17 +3127,17 @@ SortConfigurations(nsTArray<nsIWidget::C
       for (uint32_t j = 0; j < pluginsToMove.Length(); ++j) {
         if (i == j)
           continue;
         nsIntRect bounds;
         pluginsToMove[j].mChild->GetBoundsUntyped(bounds);
         nsAutoTArray<nsIntRect,1> clipRects;
         pluginsToMove[j].mChild->GetWindowClipRegion(&clipRects);
         if (HasOverlap(bounds.TopLeft(), clipRects,
-                       config->mBounds.TopLeft(),
+                       config->mBounds.ToUnknownRect().TopLeft(),
                        config->mClipRegion)) {
           foundOverlap = true;
           break;
         }
       }
       if (!foundOverlap)
         break;
     }

--- a/layout/generic/nsPluginFrame.cpp
+++ b/layout/generic/nsPluginFrame.cpp
@@ -403,17 +403,18 @@ nsPluginFrame::GetWidgetConfiguration(ns
     // geometry updates and this should not be called. But apparently we
     // have bugs where mWidget sometimes is toplevel here. Bail out.
     NS_ERROR("Plugin widgets registered for geometry updates should not be toplevel");
     return;
   }
 
   nsIWidget::Configuration* configuration = aConfigurations->AppendElement();
   configuration->mChild = mWidget;
-  configuration->mBounds = mNextConfigurationBounds;
+  configuration->mBounds =
+    LayoutDeviceIntRect::FromUnknownRect(mNextConfigurationBounds);
   configuration->mClipRegion = mNextConfigurationClipRegion;
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
   if (XRE_IsContentProcess()) {
     configuration->mWindowID = (uintptr_t)mWidget->GetNativeData(NS_NATIVE_PLUGIN_PORT);
     configuration->mVisible = mWidget->IsVisible();
   }
 #endif // defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
 }

--- a/widget/PuppetWidget.cpp
+++ b/widget/PuppetWidget.cpp
@@ -235,18 +235,18 @@ nsresult
 PuppetWidget::ConfigureChildren(const nsTArray<Configuration>& aConfigurations)
 {
   for (uint32_t i = 0; i < aConfigurations.Length(); ++i) {
     const Configuration& configuration = aConfigurations[i];
     PuppetWidget* w = static_cast<PuppetWidget*>(configuration.mChild.get());
     NS_ASSERTION(w->GetParent() == this,
                  "Configured widget is not a child");
     w->SetWindowClipRegion(configuration.mClipRegion, true);
-    nsIntRect bounds;
-    w->GetBoundsUntyped(bounds);
+    LayoutDeviceIntRect bounds;
+    w->GetBounds(bounds);
     if (bounds.Size() != configuration.mBounds.Size()) {
       w->Resize(configuration.mBounds.x, configuration.mBounds.y,
                 configuration.mBounds.width, configuration.mBounds.height,
                 true);
     } else if (bounds.TopLeft() != configuration.mBounds.TopLeft()) {
       w->Move(configuration.mBounds.x, configuration.mBounds.y);
     }
     w->SetWindowClipRegion(configuration.mClipRegion, false);

--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -4295,24 +4295,26 @@ nsWindow::ConfigureChildren(const nsTArr
       return NS_OK;
     }
 
     for (uint32_t i = 0; i < aConfigurations.Length(); ++i) {
         const Configuration& configuration = aConfigurations[i];
         nsWindow* w = static_cast<nsWindow*>(configuration.mChild.get());
         NS_ASSERTION(w->GetParent() == this,
                      "Configured widget is not a child");
+        LayoutDeviceIntRect wBounds =
+            LayoutDeviceIntRect::FromUnknownRect(w->mBounds);
         w->SetWindowClipRegion(configuration.mClipRegion, true);
-        if (w->mBounds.Size() != configuration.mBounds.Size()) {
+        if (wBounds.Size() != configuration.mBounds.Size()) {
             w->Resize(configuration.mBounds.x, configuration.mBounds.y,
                       configuration.mBounds.width, configuration.mBounds.height,
                       true);
-        } else if (w->mBounds.TopLeft() != configuration.mBounds.TopLeft()) {
+        } else if (wBounds.TopLeft() != configuration.mBounds.TopLeft()) {
             w->Move(configuration.mBounds.x, configuration.mBounds.y);
-        } 
+        }
         w->SetWindowClipRegion(configuration.mClipRegion, false);
     }
     return NS_OK;
 }
 
 nsresult
 nsWindow::SetWindowClipRegion(const nsTArray<nsIntRect>& aRects,
                               bool aIntersectWithExisting)

--- a/widget/nsIWidget.h
+++ b/widget/nsIWidget.h
@@ -1003,17 +1003,17 @@ class nsIWidget : public nsISupports {
     /**
      * This represents a command to set the bounds and clip region of
      * a child widget.
      */
     struct Configuration {
         nsCOMPtr<nsIWidget> mChild;
         uintptr_t mWindowID; // e10s specific, the unique plugin port id
         bool mVisible; // e10s specific, widget visibility
-        nsIntRect mBounds;
+        mozilla::LayoutDeviceIntRect mBounds;
         nsTArray<nsIntRect> mClipRegion;
     };
 
     /**
      * Sets the clip region of each mChild (which must actually be a child
      * of this widget) to the union of the pixel rects given in
      * mClipRegion, all relative to the top-left of the child
      * widget. Clip regions are not implemented on all platforms and only

--- a/widget/qt/nsWindow.cpp
+++ b/widget/qt/nsWindow.cpp
@@ -596,21 +596,23 @@ nsWindow::ConfigureChildren(const nsTArr
 {
     for (uint32_t i = 0; i < aConfigurations.Length(); ++i) {
         const Configuration& configuration = aConfigurations[i];
 
         nsWindow* w = static_cast<nsWindow*>(configuration.mChild);
         NS_ASSERTION(w->GetParent() == this,
                      "Configured widget is not a child");
 
-        if (w->mBounds.Size() != configuration.mBounds.Size()) {
+        LayoutDeviceIntRect wBounds =
+            LayoutDeviceIntRect::FromUnknownRect(w->mBounds);
+        if (wBounds.Size() != configuration.mBounds.Size()) {
             w->Resize(configuration.mBounds.x, configuration.mBounds.y,
                       configuration.mBounds.width, configuration.mBounds.height,
                       true);
-        } else if (w->mBounds.TopLeft() != configuration.mBounds.TopLeft()) {
+        } else if (wBounds.TopLeft() != configuration.mBounds.TopLeft()) {
             w->Move(configuration.mBounds.x, configuration.mBounds.y);
         }
     }
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsWindow::Invalidate(const nsIntRect &aRect)

--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -6525,34 +6525,34 @@ nsWindow::ConfigureChildren(const nsTArr
   // need.
   for (uint32_t i = 0; i < aConfigurations.Length(); ++i) {
     const Configuration& configuration = aConfigurations[i];
     nsWindow* w = static_cast<nsWindow*>(configuration.mChild.get());
     NS_ASSERTION(w->GetParent() == this,
                  "Configured widget is not a child");
     nsresult rv = w->SetWindowClipRegion(configuration.mClipRegion, true);
     NS_ENSURE_SUCCESS(rv, rv);
-    nsIntRect bounds;
-    w->GetBoundsUntyped(bounds);
+    LayoutDeviceIntRect bounds;
+    w->GetBounds(bounds);
     if (bounds.Size() != configuration.mBounds.Size()) {
       w->Resize(configuration.mBounds.x, configuration.mBounds.y,
                 configuration.mBounds.width, configuration.mBounds.height,
                 true);
     } else if (bounds.TopLeft() != configuration.mBounds.TopLeft()) {
       w->Move(configuration.mBounds.x, configuration.mBounds.y);
 
 
       if (gfxWindowsPlatform::GetPlatform()->GetRenderMode() ==
           gfxWindowsPlatform::RENDER_DIRECT2D ||
           GetLayerManager()->GetBackendType() != LayersBackend::LAYERS_BASIC) {
         // XXX - Workaround for Bug 587508. This will invalidate the part of the
         // plugin window that might be touched by moving content somehow. The
         // underlying problem should be found and fixed!
         nsIntRegion r;
-        r.Sub(bounds, configuration.mBounds);
+        r.Sub(bounds.ToUnknownRect(), configuration.mBounds.ToUnknownRect());
         r.MoveBy(-bounds.x,
                  -bounds.y);
         nsIntRect toInvalidate = r.GetBounds();
 
         WinUtils::InvalidatePluginAsWorkaround(w, toInvalidate);
       }
     }
     rv = w->SetWindowClipRegion(configuration.mClipRegion, false);