Fix race in BrowserAccessibilityManagerWin creation.

content/browser/accessibility/browser_accessibility_manager_win.cc

Index: content/browser/accessibility/browser_accessibility_manager_win.cc
diff --git a/content/browser/accessibility/browser_accessibility_manager_win.cc b/content/browser/accessibility/browser_accessibility_manager_win.cc
index 69c88916bd014dd5ce705e2b7fa58151919d6cb6..adb7a9196e7e02a6be6cdc5f71a971b054c76e2d 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_win.cc
@@ -19,9 +19,7 @@ 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*
@@ -30,17 +28,11 @@ BrowserAccessibilityManager::ToBrowserAccessibilityManagerWin() {
 }
 
 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() {
@@ -48,8 +40,6 @@ BrowserAccessibilityManagerWin::~BrowserAccessibilityManagerWin() {
     tracked_scroll_object_->Release();
     tracked_scroll_object_ = NULL;
   }
-  if (accessible_hwnd_)
-    accessible_hwnd_->OnManagerDeleted();
 }
 
 // static
@@ -69,19 +59,14 @@ ui::AXTreeUpdate BrowserAccessibilityManagerWin::GetEmptyDocument() {
 
 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);
 }
 
 
@@ -254,15 +239,4 @@ BrowserAccessibilityWin* BrowserAccessibilityManagerWin::GetFromUniqueIdWin(
   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