--- a/gfx/layers/composite/LayerManagerComposite.cpp
+++ b/gfx/layers/composite/LayerManagerComposite.cpp
@@ -321,17 +321,19 @@ LayerManagerComposite::Render()
 
   if (mComposer2D && mComposer2D->TryRender(mRoot, mWorldMatrix)) {
     mCompositor->EndFrameForExternalComposition(mWorldMatrix);
     return;
   }
 
   {
     PROFILER_LABEL("LayerManagerComposite", "PreRender");
-    mCompositor->GetWidget()->PreRender(this);
+    if (!mCompositor->GetWidget()->PreRender(this)) {
+      return;
+    }
   }
 
   nsIntRect clipRect;
   Rect bounds(mRenderBounds.x, mRenderBounds.y, mRenderBounds.width, mRenderBounds.height);
   Rect actualBounds;
   if (mRoot->GetClipRect()) {
     clipRect = *mRoot->GetClipRect();
     WorldTransformRect(clipRect);

--- a/widget/cocoa/nsChildView.h
+++ b/widget/cocoa/nsChildView.h
@@ -340,17 +340,17 @@ enum {
 
 - (BOOL)isPluginView;
 
 // Are we processing an NSLeftMouseDown event that will fail to click through?
 // If so, we shouldn't focus or unfocus a plugin.
 - (BOOL)isInFailingLeftClickThrough;
 
 - (void)setGLContext:(NSOpenGLContext *)aGLContext;
-- (void)preRender:(NSOpenGLContext *)aGLContext;
+- (bool)preRender:(NSOpenGLContext *)aGLContext;
 
 - (BOOL)isCoveringTitlebar;
 
 // Simple gestures support
 //
 // XXX - The swipeWithEvent, beginGestureWithEvent, magnifyWithEvent,
 // rotateWithEvent, and endGestureWithEvent methods are part of a
 // PRIVATE interface exported by nsResponder and reverse-engineering
@@ -548,17 +548,17 @@ public:
 #ifdef ACCESSIBILITY
   already_AddRefed<mozilla::a11y::Accessible> GetDocumentAccessible();
 #endif
 
   virtual void CreateCompositor();
   virtual gfxASurface* GetThebesSurface();
   virtual void PrepareWindowEffects() MOZ_OVERRIDE;
   virtual void CleanupWindowEffects() MOZ_OVERRIDE;
-  virtual void PreRender(LayerManager* aManager) MOZ_OVERRIDE;
+  virtual bool PreRender(LayerManager* aManager) MOZ_OVERRIDE;
   virtual void DrawWindowOverlay(LayerManager* aManager, nsIntRect aRect) MOZ_OVERRIDE;
 
   virtual void UpdateThemeGeometries(const nsTArray<ThemeGeometry>& aThemeGeometries);
 
   void              HidePlugin();
   void              UpdatePluginPort();
 
   void              ResetParent();

--- a/widget/cocoa/nsChildView.mm
+++ b/widget/cocoa/nsChildView.mm
@@ -2034,25 +2034,25 @@ nsChildView::PrepareWindowEffects()
 void
 nsChildView::CleanupWindowEffects()
 {
   mResizerImage = nullptr;
   mCornerMaskImage = nullptr;
   mTitlebarImage = nullptr;
 }
 
-void
+bool
 nsChildView::PreRender(LayerManager* aManager)
 {
   nsAutoPtr<GLManager> manager(GLManager::CreateGLManager(aManager));
   if (!manager) {
-    return;
+    return true;
   }
   NSOpenGLContext *glContext = (NSOpenGLContext *)manager->gl()->GetNativeData(GLContext::NativeGLContext);
-  [(ChildView*)mView preRender:glContext];
+  return [(ChildView*)mView preRender:glContext];
 }
 
 void
 nsChildView::DrawWindowOverlay(LayerManager* aManager, nsIntRect aRect)
 {
   nsAutoPtr<GLManager> manager(GLManager::CreateGLManager(aManager));
   if (manager) {
     DrawWindowOverlay(manager, aRect);
@@ -2437,17 +2437,19 @@ nsChildView::CleanupRemoteDrawing()
   mResizerImage = nullptr;
   mTitlebarImage = nullptr;
   mGLPresenter = nullptr;
 }
 
 void
 nsChildView::DoRemoteComposition(const nsIntRect& aRenderRect)
 {
-  [(ChildView*)mView preRender:mGLPresenter->GetNSOpenGLContext()];
+  if (![(ChildView*)mView preRender:mGLPresenter->GetNSOpenGLContext()]) {
+    return;
+  }
   mGLPresenter->BeginFrame(aRenderRect.Size());
 
   // Draw the result from the basic compositor.
   mBasicCompositorImage->Draw(mGLPresenter, nsIntPoint(0, 0));
 
   // DrawWindowOverlay doesn't do anything for non-GL, so it didn't paint
   // anything during the basic compositor transaction. Draw the overlay now.
   DrawWindowOverlay(mGLPresenter, aRenderRect);
@@ -2878,28 +2880,36 @@ NSEvent* gLastDragMouseDownEvent = nil;
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   mGLContext = aGLContext;
   [mGLContext retain];
 
   NS_OBJC_END_TRY_ABORT_BLOCK;
 }
 
--(void)preRender:(NSOpenGLContext *)aGLContext
-{
-  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
+- (bool)preRender:(NSOpenGLContext *)aGLContext
+{
+  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_RETURN;
 
   if (!mGLContext) {
     [self setGLContext:aGLContext];
   }
 
+  if ([[self window] isKindOfClass:[BaseWindow class]] &&
+      ![(BaseWindow*)[self window] isVisibleOrBeingShown]) {
+    // Before the window is shown, our GL context's front FBO is not
+    // framebuffer complete, so we refuse to render.
+    return false;
+  }
   [aGLContext setView:self];
   [aGLContext update];
 
-  NS_OBJC_END_TRY_ABORT_BLOCK;
+  return true;
+
+  NS_OBJC_END_TRY_ABORT_BLOCK_RETURN(false);
 }
 
 - (void)dealloc
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   [mGLContext release];
   [mPendingDirtyRects release];

--- a/widget/cocoa/nsCocoaWindow.h
+++ b/widget/cocoa/nsCocoaWindow.h
@@ -71,16 +71,18 @@ typedef struct _nsCocoaWindowList {
   BOOL mScheduledShadowInvalidation;
 
   // DPI cache. Getting the physical screen size (CGDisplayScreenSize)
   // is ridiculously slow, so we cache it in the toplevel window for all
   // descendants to use.
   float mDPI;
 
   NSTrackingArea* mTrackingArea;
+
+  BOOL mBeingShown;
 }
 
 - (void)importState:(NSDictionary*)aState;
 - (NSMutableDictionary*)exportState;
 - (void)setDrawsContentsIntoWindowFrame:(BOOL)aState;
 - (BOOL)drawsContentsIntoWindowFrame;
 - (void)setTitlebarColor:(NSColor*)aColor forActiveWindow:(BOOL)aActive;
 - (NSColor*)titlebarColorForActiveWindow:(BOOL)aActive;
@@ -90,16 +92,18 @@ typedef struct _nsCocoaWindowList {
 - (float)getDPI;
 
 - (void)mouseEntered:(NSEvent*)aEvent;
 - (void)mouseExited:(NSEvent*)aEvent;
 - (void)mouseMoved:(NSEvent*)aEvent;
 - (void)updateTrackingArea;
 - (NSView*)trackingAreaView;
 
+- (BOOL)isVisibleOrBeingShown;
+
 - (ChildView*)mainChildView;
 
 - (NSArray*)titlebarControls;
 
 @end
 
 @interface NSWindow (Undocumented)
 

--- a/widget/cocoa/nsCocoaWindow.mm
+++ b/widget/cocoa/nsCocoaWindow.mm
@@ -30,16 +30,17 @@
 #include "nsCocoaFeatures.h"
 #include "nsIScreenManager.h"
 #include "nsIWidgetListener.h"
 #include "nsIPresShell.h"
 
 #include "gfxPlatform.h"
 #include "qcms.h"
 
+#include "mozilla/AutoRestore.h"
 #include "mozilla/BasicEvents.h"
 #include "mozilla/Preferences.h"
 #include <algorithm>
 
 namespace mozilla {
 namespace layers {
 class LayerManager;
 }
@@ -2514,21 +2515,41 @@ GetDPI(NSWindow* aWindow)
   mDrawsIntoWindowFrame = NO;
   [super initWithContentRect:aContentRect styleMask:aStyle backing:aBufferingType defer:aFlag];
   mState = nil;
   mActiveTitlebarColor = nil;
   mInactiveTitlebarColor = nil;
   mScheduledShadowInvalidation = NO;
   mDPI = GetDPI(self);
   mTrackingArea = nil;
+  mBeingShown = NO;
   [self updateTrackingArea];
 
   return self;
 }
 
+- (BOOL)isVisibleOrBeingShown
+{
+  return [super isVisible] || mBeingShown;
+}
+
+- (void)orderFront:(id)sender
+{
+  AutoRestore<BOOL> saveBeingShown(mBeingShown);
+  mBeingShown = YES;
+  [super orderFront:sender];
+}
+
+- (void)makeKeyAndOrderFront:(id)sender
+{
+  AutoRestore<BOOL> saveBeingShown(mBeingShown);
+  mBeingShown = YES;
+  [super makeKeyAndOrderFront:sender];
+}
+
 - (void)dealloc
 {
   [mActiveTitlebarColor release];
   [mInactiveTitlebarColor release];
   [self removeTrackingArea];
   ChildViewMouseTracker::OnDestroyWindow(self);
   [super dealloc];
 }

--- a/widget/nsIWidget.h
+++ b/widget/nsIWidget.h
@@ -91,18 +91,18 @@ typedef void* nsNativeWidget;
 #ifdef XP_WIN
 #define NS_NATIVE_TSF_THREAD_MGR       100
 #define NS_NATIVE_TSF_CATEGORY_MGR     101
 #define NS_NATIVE_TSF_DISPLAY_ATTR_MGR 102
 #define NS_NATIVE_ICOREWINDOW          103 // winrt specific
 #endif
 
 #define NS_IWIDGET_IID \
-{ 0x1ebdb596, 0x0f90, 0x4f02, \
-  { 0x97, 0x07, 0x4e, 0xc1, 0x16, 0xcd, 0x54, 0xf6 } }
+{ 0x8e2afc1c, 0x7087, 0x4ec2, \
+  { 0xac, 0xc6, 0xd4, 0xf2, 0x3e, 0x13, 0xd2, 0xb7 } }
 
 /*
  * Window shadow styles
  * Also used for the -moz-window-shadow CSS property
  */
 
 #define NS_STYLE_WINDOW_SHADOW_NONE             0
 #define NS_STYLE_WINDOW_SHADOW_DEFAULT          1
@@ -1210,17 +1210,24 @@ class nsIWidget : public nsISupports {
     /**
      * Called when shutting down the LayerManager to clean-up any cached resources.
      *
      * Always called from the compositing thread, which may be the main-thread if
      * OMTC is not enabled.
      */
     virtual void CleanupWindowEffects() = 0;
 
-    virtual void PreRender(LayerManager* aManager) = 0;
+    /**
+     * Called before rendering using OpenGL. Returns false when the widget is
+     * not ready to be rendered (for example while the window is closed).
+     *
+     * Always called from the compositing thread, which may be the main-thread if
+     * OMTC is not enabled.
+     */
+    virtual bool PreRender(LayerManager* aManager) = 0;
 
     /**
      * Called before the LayerManager draws the layer tree.
      *
      * Always called from the compositing thread, which may be the main-thread if
      * OMTC is not enabled.
      */
     virtual void DrawWindowUnderlay(LayerManager* aManager, nsIntRect aRect) = 0;

--- a/widget/xpwidgets/nsBaseWidget.h
+++ b/widget/xpwidgets/nsBaseWidget.h
@@ -131,17 +131,17 @@ public:
                                           LayerManagerPersistence aPersistence = LAYER_MANAGER_CURRENT,
                                           bool* aAllowRetaining = nullptr);
 
   virtual CompositorParent* NewCompositorParent(int aSurfaceWidth, int aSurfaceHeight);
   virtual void            CreateCompositor();
   virtual void            CreateCompositor(int aWidth, int aHeight);
   virtual void            PrepareWindowEffects() {}
   virtual void            CleanupWindowEffects() {}
-  virtual void            PreRender(LayerManager* aManager) {}
+  virtual bool            PreRender(LayerManager* aManager) { return true; }
   virtual void            DrawWindowUnderlay(LayerManager* aManager, nsIntRect aRect) {}
   virtual void            DrawWindowOverlay(LayerManager* aManager, nsIntRect aRect) {}
   virtual mozilla::TemporaryRef<mozilla::gfx::DrawTarget> StartRemoteDrawing();
   virtual void            EndRemoteDrawing() { };
   virtual void            CleanupRemoteDrawing() { };
   virtual void            UpdateThemeGeometries(const nsTArray<ThemeGeometry>& aThemeGeometries) {}
   virtual gfxASurface*    GetThebesSurface();
   NS_IMETHOD              SetModal(bool aModal);