--- a/dom/ipc/DOMTypes.ipdlh
+++ b/dom/ipc/DOMTypes.ipdlh
@@ -91,17 +91,17 @@ struct ScreenDetails {
 };
 
 struct DimensionInfo
 {
   CSSRect rect;
   CSSSize size;
   ScreenOrientationInternal orientation;
   LayoutDeviceIntPoint clientOffset;
-  LayoutDeviceIntPoint chromeDisp;
+  LayoutDeviceIntPoint chromeOffset;
 };
 
 struct FrameScriptInfo
 {
   nsString url;
   bool runInGlobalScope;
 };
 

--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -1315,17 +1315,17 @@ mozilla::ipc::IPCResult
 TabChild::RecvUpdateDimensions(const DimensionInfo& aDimensionInfo)
 {
     if (!mRemoteFrame) {
         return IPC_OK();
     }
 
     mUnscaledOuterRect = aDimensionInfo.rect();
     mClientOffset = aDimensionInfo.clientOffset();
-    mChromeDisp = aDimensionInfo.chromeDisp();
+    mChromeOffset = aDimensionInfo.chromeOffset();
 
     mOrientation = aDimensionInfo.orientation();
     SetUnscaledInnerSize(aDimensionInfo.size());
     if (!mHasValidInnerSize &&
         aDimensionInfo.size().width != 0 &&
         aDimensionInfo.size().height != 0) {
       mHasValidInnerSize = true;
     }
@@ -1335,18 +1335,18 @@ TabChild::RecvUpdateDimensions(const Dim
 
     // Set the size on the document viewer before we update the widget and
     // trigger a reflow. Otherwise the MobileViewportManager reads the stale
     // size from the content viewer when it computes a new CSS viewport.
     nsCOMPtr<nsIBaseWindow> baseWin = do_QueryInterface(WebNavigation());
     baseWin->SetPositionAndSize(0, 0, screenSize.width, screenSize.height,
                                 nsIBaseWindow::eRepaint);
 
-    mPuppetWidget->Resize(screenRect.x + mClientOffset.x + mChromeDisp.x,
-                          screenRect.y + mClientOffset.y + mChromeDisp.y,
+    mPuppetWidget->Resize(screenRect.x + mClientOffset.x + mChromeOffset.x,
+                          screenRect.y + mClientOffset.y + mChromeOffset.y,
                           screenSize.width, screenSize.height, true);
 
     return IPC_OK();
 }
 
 mozilla::ipc::IPCResult
 TabChild::RecvSizeModeChanged(const nsSizeMode& aSizeMode)
 {
@@ -3390,18 +3390,18 @@ TabChild::RecvUIResolutionChanged(const 
     if (presContext) {
       presContext->UIResolutionChangedSync();
     }
   }
 
   ScreenIntSize screenSize = GetInnerSize();
   if (mHasValidInnerSize && oldScreenSize != screenSize) {
     ScreenIntRect screenRect = GetOuterRect();
-    mPuppetWidget->Resize(screenRect.x + mClientOffset.x + mChromeDisp.x,
-                          screenRect.y + mClientOffset.y + mChromeDisp.y,
+    mPuppetWidget->Resize(screenRect.x + mClientOffset.x + mChromeOffset.x,
+                          screenRect.y + mClientOffset.y + mChromeOffset.y,
                           screenSize.width, screenSize.height, true);
 
     nsCOMPtr<nsIBaseWindow> baseWin = do_QueryInterface(WebNavigation());
     baseWin->SetPositionAndSize(0, 0, screenSize.width, screenSize.height,
                                 nsIBaseWindow::eRepaint);
   }
 
   return IPC_OK();

--- a/dom/ipc/TabChild.h
+++ b/dom/ipc/TabChild.h
@@ -671,17 +671,17 @@ public:
 
   virtual PPaymentRequestChild*
   AllocPPaymentRequestChild() override;
 
   virtual bool
   DeallocPPaymentRequestChild(PPaymentRequestChild* aActor) override;
 
   LayoutDeviceIntPoint GetClientOffset() const { return mClientOffset; }
-  LayoutDeviceIntPoint GetChromeDisplacement() const { return mChromeDisp; };
+  LayoutDeviceIntPoint GetChromeOffset() const { return mChromeOffset; };
 
   bool IPCOpen() const { return mIPCOpen; }
 
   bool ParentIsActive() const
   {
     return mParentIsActive;
   }
 
@@ -926,17 +926,17 @@ private:
   bool mIgnoreKeyPressEvent;
   RefPtr<APZEventState> mAPZEventState;
   SetAllowedTouchBehaviorCallback mSetAllowedTouchBehaviorCallback;
   bool mHasValidInnerSize;
   bool mDestroyed;
   // Position of client area relative to the outer window
   LayoutDeviceIntPoint mClientOffset;
   // Position of tab, relative to parent widget (typically the window)
-  LayoutDeviceIntPoint mChromeDisp;
+  LayoutDeviceIntPoint mChromeOffset;
   TabId mUniqueId;
 
   // Holds the compositor options for the compositor rendering this tab,
   // once we find out which compositor that is.
   Maybe<mozilla::layers::CompositorOptions> mCompositorOptions;
 
   friend class ContentChild;
 

--- a/dom/plugins/base/nsPluginInstanceOwner.cpp
+++ b/dom/plugins/base/nsPluginInstanceOwner.cpp
@@ -991,25 +991,23 @@ NPBool nsPluginInstanceOwner::ConvertPoi
     presContext->DeviceContext()->AppUnitsPerDevPixelAtUnitFullZoom());
 
   PuppetWidget *puppetWidget = static_cast<PuppetWidget*>(widget);
   PuppetWidget *rootWidget = static_cast<PuppetWidget*>(widget->GetTopLevelWidget());
   if (!rootWidget) {
     return false;
   }
   CSSIntPoint chromeSize = CSSIntPoint::Truncate(
-    LayoutDeviceIntPoint::FromUnknownPoint(rootWidget->GetChromeDimensions()) /
-    scaleFactor);
+    rootWidget->GetChromeOffset() / scaleFactor);
   nsIntSize intScreenDims = rootWidget->GetScreenDimensions();
   CSSIntSize screenDims = CSSIntSize::Truncate(
     LayoutDeviceIntSize::FromUnknownSize(intScreenDims) / scaleFactor);
   int32_t screenH = screenDims.height;
   CSSIntPoint windowPosition = CSSIntPoint::Truncate(
-    LayoutDeviceIntPoint::FromUnknownPoint(rootWidget->GetWindowPosition()) /
-    scaleFactor);
+    rootWidget->GetWindowPosition() / scaleFactor);
 
   // Window size is tab size + chrome size.
   LayoutDeviceIntRect tabContentBounds = puppetWidget->GetBounds();
   tabContentBounds.ScaleInverseRoundOut(scaleFactor.scale);
   int32_t windowH = tabContentBounds.height + int(chromeSize.y);
 
   CSSIntPoint pluginPosition = pluginFrame->GetScreenRect().TopLeft();
 

--- a/layout/generic/nsPluginFrame.cpp
+++ b/layout/generic/nsPluginFrame.cpp
@@ -787,17 +787,17 @@ mozilla::LayoutDeviceIntPoint
 nsPluginFrame::GetRemoteTabChromeOffset()
 {
   LayoutDeviceIntPoint offset;
   if (XRE_IsContentProcess()) {
     if (nsPIDOMWindowOuter* window = GetContent()->OwnerDoc()->GetWindow()) {
       if (nsCOMPtr<nsPIDOMWindowOuter> topWindow = window->GetTop()) {
         dom::TabChild* tc = dom::TabChild::GetFrom(topWindow);
         if (tc) {
-          offset += tc->GetChromeDisplacement();
+          offset += tc->GetChromeOffset();
         }
       }
     }
   }
   return offset;
 }
 
 nsIntPoint

--- a/widget/PuppetWidget.cpp
+++ b/widget/PuppetWidget.cpp
@@ -1207,36 +1207,36 @@ PuppetWidget::SetNativeData(uint32_t aDa
     }
     break;
   default:
     NS_WARNING("SetNativeData called with unsupported data type.");
   }
 }
 #endif
 
-nsIntPoint
-PuppetWidget::GetChromeDimensions()
+LayoutDeviceIntPoint
+PuppetWidget::GetChromeOffset()
 {
   if (!GetOwningTabChild()) {
     NS_WARNING("PuppetWidget without Tab does not have chrome information.");
-    return nsIntPoint();
+    return LayoutDeviceIntPoint();
   }
-  return GetOwningTabChild()->GetChromeDisplacement().ToUnknownPoint();
+  return GetOwningTabChild()->GetChromeOffset();
 }
 
-nsIntPoint
+LayoutDeviceIntPoint
 PuppetWidget::GetWindowPosition()
 {
   if (!GetOwningTabChild()) {
-    return nsIntPoint();
+    return LayoutDeviceIntPoint();
   }
 
   int32_t winX, winY, winW, winH;
-  NS_ENSURE_SUCCESS(GetOwningTabChild()->GetDimensions(0, &winX, &winY, &winW, &winH), nsIntPoint());
-  return nsIntPoint(winX, winY) + GetOwningTabChild()->GetClientOffset().ToUnknownPoint();
+  NS_ENSURE_SUCCESS(GetOwningTabChild()->GetDimensions(0, &winX, &winY, &winW, &winH), LayoutDeviceIntPoint());
+  return LayoutDeviceIntPoint(winX, winY) + GetOwningTabChild()->GetClientOffset();
 }
 
 LayoutDeviceIntRect
 PuppetWidget::GetScreenBounds()
 {
   return LayoutDeviceIntRect(WidgetToScreenOffset(), mBounds.Size());
 }
 

--- a/widget/PuppetWidget.h
+++ b/widget/PuppetWidget.h
@@ -135,17 +135,17 @@ public:
   void SetNativeData(uint32_t aDataType, uintptr_t aVal) override;
 #endif
 
   // PuppetWidgets don't have any concept of titles.
   virtual nsresult SetTitle(const nsAString& aTitle) override
   { return NS_ERROR_UNEXPECTED; }
 
   virtual LayoutDeviceIntPoint WidgetToScreenOffset() override
-  { return LayoutDeviceIntPoint::FromUnknownPoint(GetWindowPosition() + GetChromeDimensions()); }
+  { return GetWindowPosition() + GetChromeOffset(); }
 
   int32_t RoundsWidgetCoordinatesTo() override;
 
   void InitEvent(WidgetGUIEvent& aEvent,
                  LayoutDeviceIntPoint* aPoint = nullptr);
 
   virtual nsresult DispatchEvent(WidgetGUIEvent* aEvent,
                                  nsEventStatus& aStatus) override;
@@ -230,21 +230,21 @@ public:
   {
     mDPI = aDpi;
     mRounding = aRounding;
     mDefaultScale = aScale;
   }
 
   nsIntSize GetScreenDimensions();
 
-  // Get the size of the chrome of the window that this tab belongs to.
-  nsIntPoint GetChromeDimensions();
+  // Get the offset to the chrome of the window that this tab belongs to.
+  LayoutDeviceIntPoint GetChromeOffset();
 
   // Get the screen position of the application window.
-  nsIntPoint GetWindowPosition();
+  LayoutDeviceIntPoint GetWindowPosition();
 
   virtual LayoutDeviceIntRect GetScreenBounds() override;
 
   virtual MOZ_MUST_USE nsresult
   StartPluginIME(const mozilla::WidgetKeyboardEvent& aKeyboardEvent,
                  int32_t aPanelX, int32_t aPanelY,
                  nsString& aCommitted) override;