Make panels not show on top when there is an app running in full screen mode.

chrome/browser/ui/panels/panel_window_controller_cocoa.mm

Index: chrome/browser/ui/panels/panel_window_controller_cocoa.mm
diff --git a/chrome/browser/ui/panels/panel_window_controller_cocoa.mm b/chrome/browser/ui/panels/panel_window_controller_cocoa.mm
index 06e69df40e587410dc730d05bad69c18ca377ad3..d6548840418797027837413d92458e862f28d2f2 100644
--- a/chrome/browser/ui/panels/panel_window_controller_cocoa.mm
+++ b/chrome/browser/ui/panels/panel_window_controller_cocoa.mm
@@ -112,7 +112,8 @@ enum {
   DCHECK(titlebar_view_);
   DCHECK_EQ(self, [window delegate]);
 
-  [window setLevel:NSStatusWindowLevel];
+  if (!windowShim_->panel()->manager()->is_full_screen_mode_on())
+    [window setLevel:NSStatusWindowLevel];
 
   if (base::mac::IsOSSnowLeopardOrLater()) {
     [window setCollectionBehavior:
@@ -566,6 +567,12 @@ enum {
     [NSApp deactivate];
 }
 
+- (void)fullScreenModeChanged:(bool)isFullScreenModeOn {
+  NSWindow* window = [self window];
+  [window setLevel:(isFullScreenModeOn ?
+      NSStatusWindowLevel : NSNormalWindowLevel)];
+}
+
 - (BOOL)canBecomeKeyWindow {
   // Panel can only gain focus if it is expanded. Minimized panels do not
   // participate in Cmd-~ rotation.