diff --git a/browser/native_window.h b/browser/native_window.h
index 316f6f5fe18e..a52448afedf5 100644
--- a/browser/native_window.h
+++ b/browser/native_window.h
@@ -99,6 +99,7 @@ class NativeWindow : public brightray::DefaultWebContentsDelegate,
   virtual void FlashFrame(bool flash) = 0;
   virtual void SetKiosk(bool kiosk) = 0;
   virtual bool IsKiosk() = 0;
+  virtual bool HasModalDialog() = 0;
   virtual gfx::NativeWindow GetNativeWindow() = 0;
 
   virtual bool IsClosed() const { return is_closed_; }
diff --git a/browser/native_window_mac.h b/browser/native_window_mac.h
index d1729a0ef281..0338eebefc3e 100644
--- a/browser/native_window_mac.h
+++ b/browser/native_window_mac.h
@@ -53,6 +53,7 @@ class NativeWindowMac : public NativeWindow {
   virtual void FlashFrame(bool flash) OVERRIDE;
   virtual void SetKiosk(bool kiosk) OVERRIDE;
   virtual bool IsKiosk() OVERRIDE;
+  virtual bool HasModalDialog() OVERRIDE;
   virtual gfx::NativeWindow GetNativeWindow() OVERRIDE;
 
   void NotifyWindowBlur() { NativeWindow::NotifyWindowBlur(); }
diff --git a/browser/native_window_mac.mm b/browser/native_window_mac.mm
index 47fabbfa02b1..e9c12ba976ea 100644
--- a/browser/native_window_mac.mm
+++ b/browser/native_window_mac.mm
@@ -387,6 +387,10 @@ bool NativeWindowMac::IsKiosk() {
   return is_kiosk_;
 }
 
+bool NativeWindowMac::HasModalDialog() {
+  return [window() attachedSheet] != nil;
+}
+
 gfx::NativeWindow NativeWindowMac::GetNativeWindow() {
   return window();
 }
diff --git a/browser/native_window_win.h b/browser/native_window_win.h
index 9d9ed0df61f1..a583a982e90a 100644
--- a/browser/native_window_win.h
+++ b/browser/native_window_win.h
@@ -65,6 +65,7 @@ class NativeWindowWin : public NativeWindow,
   virtual void FlashFrame(bool flash) OVERRIDE;
   virtual void SetKiosk(bool kiosk) OVERRIDE;
   virtual bool IsKiosk() OVERRIDE;
+  virtual bool HasModalDialog() OVERRIDE;
   virtual gfx::NativeWindow GetNativeWindow() OVERRIDE;
 
   void OnMenuCommand(int position, HMENU menu);