Fix race in BrowserAccessibilityManagerWin creation.

content/browser/accessibility/browser_accessibility_manager_win.cc

 // Copyright (c) 2012 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/accessibility/browser_accessibility_manager_win.h"
 
 #include "base/command_line.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/windows_version.h"
 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
 #include "content/browser/accessibility/browser_accessibility_win.h"
 #include "content/browser/renderer_host/legacy_render_widget_host_win.h"
 #include "content/common/accessibility_messages.h"
 
 namespace content {
 
 // static
 BrowserAccessibilityManager* BrowserAccessibilityManager::Create(
     const ui::AXTreeUpdate& initial_tree,
     BrowserAccessibilityDelegate* delegate,
     BrowserAccessibilityFactory* factory) {
-  return new BrowserAccessibilityManagerWin(
-      content::LegacyRenderWidgetHostHWND::Create(GetDesktopWindow()).get(),
-      NULL, initial_tree, delegate, factory);
+  return new BrowserAccessibilityManagerWin(initial_tree, delegate, factory);
 }
 
 BrowserAccessibilityManagerWin*
 BrowserAccessibilityManager::ToBrowserAccessibilityManagerWin() {
   return static_cast<BrowserAccessibilityManagerWin*>(this);
 }
 
 BrowserAccessibilityManagerWin::BrowserAccessibilityManagerWin(
-    LegacyRenderWidgetHostHWND* accessible_hwnd,
-    IAccessible* parent_iaccessible,
     const ui::AXTreeUpdate& initial_tree,
     BrowserAccessibilityDelegate* delegate,
     BrowserAccessibilityFactory* factory)
     : BrowserAccessibilityManager(initial_tree, delegate, factory),
-      parent_hwnd_(accessible_hwnd->GetParent()),
-      parent_iaccessible_(parent_iaccessible),
-      tracked_scroll_object_(NULL),
-      accessible_hwnd_(accessible_hwnd) {
-  accessible_hwnd_->set_browser_accessibility_manager(this);
+      tracked_scroll_object_(NULL) {
 }
 
 BrowserAccessibilityManagerWin::~BrowserAccessibilityManagerWin() {
   if (tracked_scroll_object_) {
     tracked_scroll_object_->Release();
     tracked_scroll_object_ = NULL;
   }
-  if (accessible_hwnd_)
-    accessible_hwnd_->OnManagerDeleted();
 }
 
 // static
 ui::AXTreeUpdate BrowserAccessibilityManagerWin::GetEmptyDocument() {
   ui::AXNodeData empty_document;
   empty_document.id = 0;
   empty_document.role = ui::AX_ROLE_ROOT_WEB_AREA;
   empty_document.state =
       (1 << ui::AX_STATE_ENABLED) |
       (1 << ui::AX_STATE_READ_ONLY) |
       (1 << ui::AX_STATE_BUSY);
 
   ui::AXTreeUpdate update;
   update.nodes.push_back(empty_document);
   return update;
 }
 
 void BrowserAccessibilityManagerWin::MaybeCallNotifyWinEvent(DWORD event,
                                                              LONG child_id) {
-  // Don't fire events if this view isn't hooked up to its parent.
-  if (!parent_iaccessible())
+  if (!delegate())
     return;
 
-  // If on Win 7 and complete accessibility is enabled, use the fake child HWND
-  // to use as the root of the accessibility tree. See comments above
-  // LegacyRenderWidgetHostHWND for details.
-  if (BrowserAccessibilityStateImpl::GetInstance()->IsAccessibleBrowser()) {
-    DCHECK(accessible_hwnd_);
-    parent_hwnd_ = accessible_hwnd_->hwnd();
-    parent_iaccessible_ = accessible_hwnd_->window_accessible();
-  }
-  ::NotifyWinEvent(event, parent_hwnd(), OBJID_CLIENT, child_id);
+  HWND parent_hwnd = delegate()->GetAccessibleParentHWND();
+  if (!parent_hwnd)
+    return;
+
+  ::NotifyWinEvent(event, parent_hwnd, OBJID_CLIENT, child_id);
 }
 
 
 void BrowserAccessibilityManagerWin::OnNodeCreated(ui::AXNode* node) {
   BrowserAccessibilityManager::OnNodeCreated(node);
   BrowserAccessibility* obj = GetFromAXNode(node);
   LONG unique_id_win = obj->ToBrowserAccessibilityWin()->unique_id_win();
   unique_id_to_ax_id_map_[unique_id_win] = obj->GetId();
 }
 
@@ skipping 152 matching lines @@
   base::hash_map<LONG, int32>::iterator iter =
       unique_id_to_ax_id_map_.find(unique_id_win);
   if (iter != unique_id_to_ax_id_map_.end()) {
     BrowserAccessibility* result = GetFromID(iter->second);
     if (result)
       return result->ToBrowserAccessibilityWin();
   }
   return NULL;
 }
 
-void BrowserAccessibilityManagerWin::OnAccessibleHwndDeleted() {
-  // If the AccessibleHWND is deleted, |parent_hwnd_| and
-  // |parent_iaccessible_| are no longer valid either, since they were
-  // derived from AccessibleHWND. We don't have to restore them to
-  // previous values, though, because this should only happen
-  // during the destruct sequence for this window.
-  accessible_hwnd_ = NULL;
-  parent_hwnd_ = NULL;
-  parent_iaccessible_ = NULL;
-}
-
 }  // namespace content