Fixed a fullscreen race condition on OSX

chrome/browser/ui/cocoa/browser_window_controller.mm

Index: chrome/browser/ui/cocoa/browser_window_controller.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index c660dfd7a1823b82e1424a373f390127c8acc0d6..efc9f31c1637a1b9f76258898c6dad6590301a92 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -1817,6 +1817,14 @@ willAnimateFromState:(BookmarkBar::State)oldState
           [controller getDesiredToolbarHeightCompression]];
 }
 
+// (Needed for |BrowserWindowFullscreenTransitionDelegate| protocol.)
+- (void)finishedExitingFullscreen {
+  if (appKitDidExitFullscreen_) {
+    [self windowDidExitFullScreen:nil];
+    appKitDidExitFullscreen_ = NO;
+  }
+}
+
 // (Private/TestingAPI)
 - (void)resetWindowGrowthState {
   windowTopGrowth_ = 0;