Fix a browser, renderer, plugin deadlock caused by the change to reparent plugin windows in the b...

content/browser/plugin_process_host.cc

 // Copyright (c) 2011 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 "content/browser/plugin_process_host.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_POSIX)
 #include <utility>  // for pair<>
@@ skipping 30 matching lines @@
 
 #if defined(OS_MACOSX)
 #include "base/mac/mac_util.h"
 #include "content/common/plugin_carbon_interpose_constants_mac.h"
 #include "ui/gfx/rect.h"
 #endif
 
 #if defined(OS_WIN)
 #include "webkit/plugins/npapi/webplugin_delegate_impl.h"
 
+namespace {
+
+void ReparentPluginWindowHelper(HWND window, HWND parent) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  int window_style = WS_CHILD;
+  if (!webkit::npapi::WebPluginDelegateImpl::IsDummyActivationWindow(window))
+    window_style |= WS_CLIPCHILDREN | WS_CLIPSIBLINGS;
+
+  ::SetWindowLongPtr(window, GWL_STYLE, window_style);
+  ::SetParent(window, parent);
+}
+
+}  // namespace
+
 void PluginProcessHost::OnPluginWindowDestroyed(HWND window, HWND parent) {
   // The window is destroyed at this point, we just care about its parent, which
   // is the intermediate window we created.
   std::set<HWND>::iterator window_index =
       plugin_parent_windows_set_.find(parent);
   if (window_index == plugin_parent_windows_set_.end())
     return;
 
   plugin_parent_windows_set_.erase(window_index);
   PostMessage(parent, WM_CLOSE, 0, 0);
 }
 
 void PluginProcessHost::AddWindow(HWND window) {
   plugin_parent_windows_set_.insert(window);
 }
 
 void PluginProcessHost::OnReparentPluginWindow(HWND window, HWND parent) {
   // Reparent only to our process.
   DWORD process_id = 0;
   ::GetWindowThreadProcessId(parent, &process_id);
   if (process_id != ::GetCurrentProcessId())
     return;
 
-  if (webkit::npapi::WebPluginDelegateImpl::IsDummyActivationWindow(window)) {
-    ::SetWindowLongPtr(window, GWL_STYLE, WS_CHILD);
-  } else {
-    ::SetWindowLongPtr(window, GWL_STYLE, WS_CHILD | WS_CLIPCHILDREN |
-                       WS_CLIPSIBLINGS);
-  }
-  ::SetParent(window, parent);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      NewRunnableFunction(ReparentPluginWindowHelper, window, parent));
 }
 #endif  // defined(OS_WIN)
 
 #if defined(TOOLKIT_USES_GTK)
 void PluginProcessHost::OnMapNativeViewId(gfx::NativeViewId id,
                                           gfx::PluginWindowHandle* output) {
   *output = 0;
   GtkNativeViewManager::GetInstance()->GetXIDForId(output, id);
 }
 #endif  // defined(TOOLKIT_USES_GTK)
@@ skipping 254 matching lines @@
   }
 }
 
 void PluginProcessHost::OnChannelCreated(
     const IPC::ChannelHandle& channel_handle) {
   Client* client = sent_requests_.front();
 
   client->OnChannelOpened(channel_handle);
   sent_requests_.pop();
 }