Create only a single LegacyRenderWidgetHostHWND per WebContentsViewAura.

content/browser/web_contents/web_contents_view_aura.cc

Index: content/browser/web_contents/web_contents_view_aura.cc
diff --git a/content/browser/web_contents/web_contents_view_aura.cc b/content/browser/web_contents/web_contents_view_aura.cc
index ecbe02ca04e5d4dd798d5a9a6599dbc6e03229c1..e2ff3c732bae31613844b8dbd442347114f36e63 100644
--- a/content/browser/web_contents/web_contents_view_aura.cc
+++ b/content/browser/web_contents/web_contents_view_aura.cc
@@ -66,10 +66,17 @@
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/image/image_png_rep.h"
 #include "ui/gfx/image/image_skia.h"
+#include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/screen.h"
 #include "ui/wm/public/drag_drop_client.h"
 #include "ui/wm/public/drag_drop_delegate.h"
 
+#if defined(OS_WIN)
+#include "content/browser/accessibility/browser_accessibility_manager.h"
+#include "content/browser/accessibility/browser_accessibility_win.h"
+#include "ui/base/win/hidden_window.h"
+#endif
+
 namespace content {
 WebContentsView* CreateWebContentsView(
     WebContentsImpl* web_contents,
@@ -641,6 +648,10 @@ class WebContentsViewAura::WindowObserver
 #if defined(OS_WIN)
       if (!window->GetRootWindow()->HasObserver(this))
         window->GetRootWindow()->AddObserver(this);
+      if (view_->legacy_hwnd_) {
+        view_->legacy_hwnd_->UpdateParent(
+            window->GetHost()->GetAcceleratedWidget());
+      }
 #endif
     }
   }
@@ -660,6 +671,11 @@ class WebContentsViewAura::WindowObserver
           root_children[i]->RemoveObserver(this);
         }
       }
+
+      // Update the legacy window's parent temporarily to the desktop window.
+      // It will eventually get reparented to the right root.
+      if (view_->legacy_hwnd_)
+        view_->legacy_hwnd_->UpdateParent(::GetDesktopWindow());

[ananta, 2014/09/23 20:14:06]

I know that this is a copy of the existing code in
RenderWidgetHostViewAura::RemovingFromRootWindow. However it may be better to
reparent to the hidden window instead. This is to avoid bugs like unwanted
buttons showing up on the taskbar because the legacy_hwnd becomes a top level
window.

[dmazzoni, 2014/09/24 22:57:52]

Makes sense, done.

 #endif
     }
   }
@@ -1013,6 +1029,8 @@ void WebContentsViewAura::SizeContents(const gfx::Size& size) {
   if (bounds.size() != size) {
     bounds.set_size(size);
     window_->SetBounds(bounds);
+    if (legacy_hwnd_)
+      legacy_hwnd_->SetBounds(window_->GetBoundsInRootWindow());
   } else {
     // Our size matches what we want but the renderers size may not match.
     // Pretend we were resized so that the renderers size is updated too.
@@ -1106,6 +1124,15 @@ void WebContentsViewAura::CreateView(
   // platforms as well.
   if (delegate_)
     drag_dest_delegate_ = delegate_->GetDragDestDelegate();
+
+#if defined(OS_WIN)
+  HWND parent_hwnd;
+  if (context && context->GetHost())
+    parent_hwnd = context->GetHost()->GetAcceleratedWidget();
+  else
+    parent_hwnd = ::GetDesktopWindow();

[ananta, 2014/09/23 20:14:06]

It would be good to know when context is going to be NULL when this function is
called. Would be better to avoid creating the legacy hwnd if we don't have a
context.

[dmazzoni, 2014/09/24 22:57:52]

The comment above says that sometimes object hierarchies are build before
they're attached to a widget. I think it'd be better for accessibility if we had
created the HWND here. We already have code to reparent it in
OnWindowAddedToRootWindow.

+  legacy_hwnd_.reset(LegacyRenderWidgetHostHWND::Create(parent_hwnd, this));
+#endif
 }
 
 RenderWidgetHostViewBase* WebContentsViewAura::CreateViewForWidget(
@@ -1146,12 +1173,22 @@ RenderWidgetHostViewBase* WebContentsViewAura::CreateViewForWidget(
   }
 
   AttachTouchEditableToRenderView();
+
+#if defined(OS_WIN)
+  view->SetLegacyRenderWidgetHostHWND(legacy_hwnd_.get());
+#endif
+
   return view;
 }
 
 RenderWidgetHostViewBase* WebContentsViewAura::CreateViewForPopupWidget(
     RenderWidgetHost* render_widget_host) {
-  return new RenderWidgetHostViewAura(render_widget_host);
+  RenderWidgetHostViewAura* view =
+      new RenderWidgetHostViewAura(render_widget_host);
+#if defined(OS_WIN)
+  view->SetLegacyRenderWidgetHostHWND(legacy_hwnd_.get());
+#endif
+  return view;
 }
 
 void WebContentsViewAura::SetPageTitle(const base::string16& title) {
@@ -1621,6 +1658,35 @@ void WebContentsViewAura::UpdateWebContentsVisibility(bool visible) {
     if (web_contents_->should_normally_be_visible())
       web_contents_->WasHidden();
   }
+
+#if defined(OS_WIN)
+  if (!legacy_hwnd_)
+    return;
+
+  if (visible) {
+    legacy_hwnd_->UpdateParent(
+        GetNativeView()->GetHost()->GetAcceleratedWidget());
+    legacy_hwnd_->SetBounds(window_->GetBoundsInRootWindow());
+    legacy_hwnd_->Show();
+  } else {
+    // We reparent the legacy Chrome_RenderWidgetHostHWND window to the global
+    // hidden window on the same lines as Windowed plugin windows.
+    legacy_hwnd_->UpdateParent(ui::GetHiddenWindow());
+    legacy_hwnd_->Hide();
+  }
+#endif
+}
+
+#if defined(OS_WIN)
+gfx::NativeViewAccessible
+WebContentsViewAura::GetNativeViewAccessible() {
+  BrowserAccessibilityManager* manager =
+      web_contents_->GetRootBrowserAccessibilityManager();
+  if (!manager)
+    return NULL;
+
+  return manager->GetRoot()->ToBrowserAccessibilityWin();
 }
+#endif
 
 }  // namespace content