Prevented connecting drag drop events to a SwappedOut RenderViewHost in WebContentsViewGtk

content/browser/web_contents/web_contents_view_gtk.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/web_contents/web_contents_view_gtk.h"
 
 #include <gdk/gdk.h>
 #include <gdk/gdkkeysyms.h>
 #include <gtk/gtk.h>
 
@@ skipping 110 matching lines @@
     // this actually is happening (and somebody isn't accidentally creating the
     // view twice), we check for the RVH Factory, which will be set when we're
     // making special ones (which go along with the special views).
     DCHECK(RenderViewHostFactory::has_factory());
     return render_widget_host->GetView();
   }
 
   RenderWidgetHostView* view =
       RenderWidgetHostView::CreateViewForWidget(render_widget_host);
   view->InitAsChild(NULL);
+  if (render_widget_host->IsRenderView()) {
+    RenderViewHost* rvh = RenderViewHost::From(render_widget_host);
+    // A swapped out RenderViewHost is not visible, and so there is no reason
+    // to connect events to it, or use it as a WebDragDest (It won't be able
+    // to receive drag updates, and may break drag and drop in a window).
+    if (web_contents_->GetRenderManagerForTesting()->IsSwappedOut(rvh)) {

[Fady Samuel, 2013/02/13 21:15:22]

This looks wrong...GetRenderManagerForTesting is supposed to be used in testing
only (hence the name).

However, I don't necessarily have a better solution. I'll let Evan guide you on
this one. 

[Charlie Reis, 2013/02/20 06:42:45]

Fady's right-- this would be a layering violation.  RenderViewHostManager is not
supposed to be exposed outside WebContentsImpl.

An alternative is to use RenderViewHostImpl::is_swapped_out(), but I think
that's just masking the underlying problem.  This method shouldn't be called
with a swapped out RVH in the first place.

In most cases, we filter out the messages sent to/from a swapped out RVH (see
swapped_out_messages.cc).  Is there a comparable place we could be preventing
this bug at an earlier stage?

+      return view;
+    }
+  }
   gfx::NativeView content_view = view->GetNativeView();
   g_signal_connect(content_view, "focus", G_CALLBACK(OnFocusThunk), this);
   g_signal_connect(content_view, "leave-notify-event",
                    G_CALLBACK(OnLeaveNotify), web_contents_);
   g_signal_connect(content_view, "motion-notify-event",
                    G_CALLBACK(OnMouseMove), web_contents_);
   g_signal_connect(content_view, "scroll-event",
                    G_CALLBACK(OnMouseScroll), web_contents_);
   gtk_widget_add_events(content_view, GDK_LEAVE_NOTIFY_MASK |
                         GDK_POINTER_MOTION_MASK);
@@ skipping 245 matching lines @@
   // We manually tell our RWHV to resize the renderer content.  This avoids
   // spurious resizes from GTK+.
   RenderWidgetHostView* rwhv = web_contents_->GetRenderWidgetHostView();
   if (rwhv)
     rwhv->SetSize(size);
   if (web_contents_->GetInterstitialPage())
     web_contents_->GetInterstitialPage()->SetSize(size);
 }
 
 }  // namespace content