Only unset the kWebPluginDelegateProperty property after calling the plugin's...

webkit/glue/plugins/webplugin_delegate_impl.cc

 // Copyright (c) 2006-2008 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 "webkit/glue/plugins/webplugin_delegate_impl.h"
 
 #include <string>
 #include <vector>
 
 #include "base/file_util.h"
@@ skipping 837 matching lines @@
                  RDW_UPDATENOW | RDW_INVALIDATE | RDW_ALLCHILDREN | RDW_FRAME);
     return FALSE;
   }
 
   // Maintain a local/global stack for the g_current_plugin_instance variable
   // as this may be a nested invocation.
   WebPluginDelegateImpl* last_plugin_instance = g_current_plugin_instance;
 
   g_current_plugin_instance = delegate;
 
-  switch (message) {
-    case WM_NCDESTROY: {
-      RemoveProp(hwnd, kWebPluginDelegateProperty);
-      ATOM plugin_name_atom = reinterpret_cast  <ATOM>(
-          RemoveProp(hwnd, kPluginNameAtomProperty));
-      if (plugin_name_atom != 0)
-        GlobalDeleteAtom(plugin_name_atom);
-      ClearThrottleQueueForWindow(hwnd);
-      break;
-    }
-    // Flash may flood the message queue with WM_USER+1 message causing 100% CPU
-    // usage.  See https://bugzilla.mozilla.org/show_bug.cgi?id=132759.  We
-    // prevent this by throttling the messages.
-    case WM_USER + 1: {
-      if (delegate->GetQuirks() & PLUGIN_QUIRK_THROTTLE_WM_USER_PLUS_ONE) {
-        WebPluginDelegateImpl::ThrottleMessage(delegate->plugin_wnd_proc_, hwnd,
-                                               message, wparam, lparam);
-        g_current_plugin_instance = last_plugin_instance;
-        return FALSE;
-      }
-      break;
-    }
-    default: {
-      break;
-    }
+  // Flash may flood the message queue with WM_USER+1 message causing 100% CPU
+  // usage.  See https://bugzilla.mozilla.org/show_bug.cgi?id=132759.  We
+  // prevent this by throttling the messages.
+  if (message == WM_USER + 1 &&
+      delegate->GetQuirks() & PLUGIN_QUIRK_THROTTLE_WM_USER_PLUS_ONE) {
+    WebPluginDelegateImpl::ThrottleMessage(delegate->plugin_wnd_proc_, hwnd,
+                                           message, wparam, lparam);
+    g_current_plugin_instance = last_plugin_instance;
+    return FALSE;
   }
 
   delegate->last_message_ = message;
   delegate->is_calling_wndproc = true;
 
   if (!delegate->user_gesture_message_posted_ &&
        IsUserGestureMessage(message)) {
     delegate->user_gesture_message_posted_ = true;
 
     delegate->instance()->PushPopupsEnabledState(true);
 
     MessageLoop::current()->PostDelayedTask(FROM_HERE,
         delegate->user_gesture_msg_factory_.NewRunnableMethod(
             &WebPluginDelegateImpl::OnUserGestureEnd),
         kWindowedPluginPopupTimerMs);
   }
 
   LRESULT result = CallWindowProc(delegate->plugin_wnd_proc_, hwnd, message,
                                   wparam, lparam);
   delegate->is_calling_wndproc = false;
   g_current_plugin_instance = last_plugin_instance;
+
+  if (message == WM_NCDESTROY) {
+    RemoveProp(hwnd, kWebPluginDelegateProperty);
+    ATOM plugin_name_atom = reinterpret_cast  <ATOM>(
+        RemoveProp(hwnd, kPluginNameAtomProperty));
+    if (plugin_name_atom != 0)
+      GlobalDeleteAtom(plugin_name_atom);
+    ClearThrottleQueueForWindow(hwnd);
+  }
+
   return result;
 }
 
 void WebPluginDelegateImpl::WindowlessUpdateGeometry(
     const gfx::Rect& window_rect,
     const gfx::Rect& clip_rect) {
   // Only resend to the instance if the geometry has changed.
   if (window_rect == window_rect_ && clip_rect == clip_rect_)
     return;
 
@@ skipping 280 matching lines @@
 
   // It is ok to pass NULL here to GetCursor as we are not looking for cursor
   // types defined by Webkit.
   HCURSOR previous_cursor =
       g_current_plugin_instance->current_windowless_cursor_.GetCursor(NULL);
 
   g_current_plugin_instance->current_windowless_cursor_.InitFromExternalCursor(
       cursor);
   return previous_cursor;
 }