Only request full-screen once per plugin window

chrome/browser/plugin_process_host_mac.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <Carbon/Carbon.h>
 
 #include "build/build_config.h"
 
 #include <vector>
 
@@ skipping 14 matching lines @@
                                            gfx::Rect window_rect,
                                            bool modal) {
   plugin_visible_windows_set_.insert(window_id);
   if (modal)
     plugin_modal_windows_set_.insert(window_id);
   CGRect window_bounds = {
     { window_rect.x(), window_rect.y() },
     { window_rect.width(), window_rect.height() }
   };
   CGRect main_display_bounds = CGDisplayBounds(CGMainDisplayID());
-  if (CGRectEqualToRect(window_bounds, main_display_bounds)) {
+  if (CGRectEqualToRect(window_bounds, main_display_bounds) &&
+      (plugin_fullscreen_windows_set_.find(window_id) ==
+       plugin_fullscreen_windows_set_.end())) {
     plugin_fullscreen_windows_set_.insert(window_id);
     // If the plugin has just shown a window that's the same dimensions as
     // the main display, hide the menubar so that it has the whole screen.
+    // (but only if we haven't already seen this fullscreen window, since
+    // otherwise our refcounting can get skewed).
     ChromeThread::PostTask(
         ChromeThread::UI, FROM_HERE,
         NewRunnableFunction(mac_util::RequestFullScreen));
   }
 }
 
 void PluginProcessHost::OnPluginHideWindow(uint32 window_id,
                                            gfx::Rect window_rect) {
   plugin_visible_windows_set_.erase(window_id);
   plugin_modal_windows_set_.erase(window_id);
@@ skipping 15 matching lines @@
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
 
   // If our plugin process has any modal windows up, we need to bring it forward
   // so that they act more like an in-process modal window would.
   if (!plugin_modal_windows_set_.empty()) {
     ChromeThread::PostTask(
         ChromeThread::UI, FROM_HERE,
         NewRunnableFunction(mac_util::ActivateProcess, handle()));
   }
 }