Revert 276950 "Fix race in BrowserAccessibilityManagerWin creation."

Reverting on branch until fix available

> Fix race in BrowserAccessibilityManagerWin creation.
> 
> Previously, BrowserAccessibilityManagerWin needed its parent
> HWND and parent IAccessible upon construction, and if RWHVA
> didn't have those, it didn't create the BAMW. This resulted
> in at least two races:
> 
> * If an accessibility tree update came from the renderer
> but the BAMW wasn't created because the window wasn't available,
> the tree update would get discarded - possibly leading to an
> assertion failure / renderer crash later on the next update
> from being out of sync.
> 
> * If we tried to create the BAMW before the LegacyRWHH existed,
> we would fall through and create a BAM instead of a BAMW,
> making that whole tab inaccessible.
> 
> To fix both issues, we always create a BAMW when needed, and
> we update the BAMW with the LegacyRWHH as soon as it's
> available.
> 
> BUG=372478,379019
> NOTRY=true
> 
> Review URL: https://codereview.chromium.org/329053004

TBR=dmazzoni@chromium.org

Review URL: https://codereview.chromium.org/331073002

git-svn-id: svn://svn.chromium.org/chrome/branches/2051/src@277295 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 25 insertions, 36 deletions

diff --git a/content/browser/accessibility/browser_accessibility_manager_win.cc b/content/browser/accessibility/browser_accessibility_manager_win.cc
index 974b033..9aa5d4a 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_win.cc
@@ -37,14 +37,12 @@ BrowserAccessibilityManagerWin::BrowserAccessibilityManagerWin(
     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) {
   ui::win::CreateATLModuleIfNeeded();
-  if (accessible_hwnd_) {
-    accessible_hwnd_->set_browser_accessibility_manager(this);
-    parent_hwnd_ = accessible_hwnd->GetParent();
-  }
+  accessible_hwnd_->set_browser_accessibility_manager(this);
 }
 
 BrowserAccessibilityManagerWin::~BrowserAccessibilityManagerWin() {
@@ -71,17 +69,10 @@ ui::AXTreeUpdate BrowserAccessibilityManagerWin::GetEmptyDocument() {
   return update;
 }
 
-void BrowserAccessibilityManagerWin::SetAccessibleHWND(
-    LegacyRenderWidgetHostHWND* accessible_hwnd) {
-  accessible_hwnd_ = accessible_hwnd;
-  accessible_hwnd_->set_browser_accessibility_manager(this);
-  parent_hwnd_ = accessible_hwnd->GetParent();
-}
-
 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() || !parent_hwnd())
+  if (!parent_iaccessible())
     return;
 
   // If on Win 7 and complete accessibility is enabled, use the fake child HWND
diff --git a/content/browser/accessibility/browser_accessibility_manager_win.h b/content/browser/accessibility/browser_accessibility_manager_win.h
index 90914db..18260e4 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.h
+++ b/content/browser/accessibility/browser_accessibility_manager_win.h
@@ -40,8 +40,6 @@ class CONTENT_EXPORT BrowserAccessibilityManagerWin
     parent_iaccessible_ = parent_iaccessible;
   }
 
-  void SetAccessibleHWND(LegacyRenderWidgetHostHWND* accessible_hwnd);
-
   // Calls NotifyWinEvent if the parent window's IAccessible pointer is known.
   void MaybeCallNotifyWinEvent(DWORD event, LONG child_id);
 
diff --git a/content/browser/accessibility/browser_accessibility_win.cc b/content/browser/accessibility/browser_accessibility_win.cc
index 60728e0..e98ae71 100644
--- a/content/browser/accessibility/browser_accessibility_win.cc
+++ b/content/browser/accessibility/browser_accessibility_win.cc
@@ -739,9 +739,6 @@ STDMETHODIMP BrowserAccessibilityWin::get_windowHandle(HWND* window_handle) {
     return E_INVALIDARG;
 
   *window_handle = manager()->ToBrowserAccessibilityManagerWin()->parent_hwnd();
-  if (!*window_handle)
-    return E_FAIL;
-
   return S_OK;
 }
 
@@ -995,8 +992,6 @@ STDMETHODIMP BrowserAccessibilityWin::get_imagePosition(
   if (coordinate_type == IA2_COORDTYPE_SCREEN_RELATIVE) {
     HWND parent_hwnd =
         manager()->ToBrowserAccessibilityManagerWin()->parent_hwnd();
-    if (!parent_hwnd)
-      return E_FAIL;
     POINT top_left = {0, 0};
     ::ClientToScreen(parent_hwnd, &top_left);
     *x = GetLocation().x() + top_left.x;
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index ad3e95f..44d57f5 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -999,11 +999,6 @@ void RenderWidgetHostViewAura::InternalSetBounds(const gfx::Rect& rect) {
     if (!legacy_render_widget_host_HWND_) {
       legacy_render_widget_host_HWND_ = LegacyRenderWidgetHostHWND::Create(
           reinterpret_cast<HWND>(GetNativeViewId()));
-      BrowserAccessibilityManagerWin* manager =
-          static_cast<BrowserAccessibilityManagerWin*>(
-              GetBrowserAccessibilityManager());
-      if (manager)
-        manager->SetAccessibleHWND(legacy_render_widget_host_HWND_.get());
     }
     if (legacy_render_widget_host_HWND_) {
       legacy_render_widget_host_HWND_->SetBounds(
@@ -1231,23 +1226,33 @@ InputEventAckState RenderWidgetHostViewAura::FilterInputEvent(
 }
 
 void RenderWidgetHostViewAura::CreateBrowserAccessibilityManagerIfNeeded() {
+  if (GetBrowserAccessibilityManager())
+    return;
+
+  BrowserAccessibilityManager* manager = NULL;
 #if defined(OS_WIN)
-  if (!GetBrowserAccessibilityManager()) {
-    gfx::NativeViewAccessible accessible_parent =
-        host_->GetParentNativeViewAccessible();
-    LegacyRenderWidgetHostHWND* parent_hwnd =
-        legacy_render_widget_host_HWND_.get();
-    SetBrowserAccessibilityManager(new BrowserAccessibilityManagerWin(
+  aura::WindowTreeHost* host = window_->GetHost();
+  if (!host)
+    return;
+  HWND hwnd = host->GetAcceleratedWidget();
+
+  // The accessible_parent may be NULL at this point. The WebContents will pass
+  // it down to this instance (by way of the RenderViewHost and
+  // RenderWidgetHost) when it is known. This instance will then set it on its
+  // BrowserAccessibilityManager.
+  gfx::NativeViewAccessible accessible_parent =
+      host_->GetParentNativeViewAccessible();
+
+  if (legacy_render_widget_host_HWND_) {
+    manager = new BrowserAccessibilityManagerWin(
         legacy_render_widget_host_HWND_.get(), accessible_parent,
-        BrowserAccessibilityManagerWin::GetEmptyDocument(), host_));
+        BrowserAccessibilityManagerWin::GetEmptyDocument(), host_);
   }
 #else
-  if (!GetBrowserAccessibilityManager()) {
-    SetBrowserAccessibilityManager(
-        BrowserAccessibilityManager::Create(
-            BrowserAccessibilityManager::GetEmptyDocument(), host_));
-  }
+  manager = BrowserAccessibilityManager::Create(
+      BrowserAccessibilityManager::GetEmptyDocument(), host_);
 #endif
+  SetBrowserAccessibilityManager(manager);
 }
 
 gfx::GLSurfaceHandle RenderWidgetHostViewAura::GetCompositingSurface() {