From 37319ac05ac6b80724b7539b237b25c3997a58ef Mon Sep 17 00:00:00 2001
From: Xidorn Quan <quanxunzhen@gmail.com>
Date: Tue, 2 Jun 2015 09:22:49 +1200
Subject: [PATCH] Bug 1168274 part 1 - Avoid triggering window reflow for
 hiding margins when entering fullscreen on Windows. r=jimm

--HG--
extra : source : a1d29ea748b8d0b8881a5308aebd37149485ec7a
---
 widget/windows/nsWindow.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/widget/windows/nsWindow.cpp b/widget/windows/nsWindow.cpp
index df0511de6d65..ddcc0517a4bc 100644
--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -2868,7 +2868,9 @@ nsWindow::MakeFullScreen(bool aFullScreen, nsIScreen* aTargetScreen)
     SetSizeMode(mOldSizeMode);
   }
 
-  UpdateNonClientMargins();
+  // If we are going fullscreen, the window size continues to change
+  // and the window will be reflow again then.
+  UpdateNonClientMargins(mSizeMode, /* Reflow */ !aFullScreen);
 
   bool visible = mIsVisible;
   if (mOldSizeMode == nsSizeMode_Normal)