Fix a crash which occurs while dragging tabs back to the window where they originated from.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
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 a59880e6a98cec1506666c278943ce2fdaa17069..023e45593bcb8348602be5de9014b6a8b0989143 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -585,8 +585,10 @@ void RenderWidgetHostViewAura::WasShown() {
     // window before reparenting any plugins. This ensures that the plugin
     // windows stay on top of the child Zorder in the parent and receive
     // mouse events, etc.
-    legacy_render_widget_host_HWND_->UpdateParent(
-        GetNativeView()->GetHost()->GetAcceleratedWidget());
+    if (GetNativeView()->GetHost()) {

[sky, 2014/09/22 14:57:36]

If this isn't true, when does the parent get updated?

[ananta, 2014/09/22 15:12:18]

4On 2014/09/22 14:57:36, sky wrote:
This should not happen with the other change in this patch. Will revert this
file

+      legacy_render_widget_host_HWND_->UpdateParent(
+          GetNativeView()->GetHost()->GetAcceleratedWidget());
+    }
     legacy_render_widget_host_HWND_->SetBounds(
         window_->GetBoundsInRootWindow());
   }