Add a factory function to create WebContentsView implementations.

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 60 matching lines @@
   }
 
   delegate->ContentsZoomChange(event->direction == GDK_SCROLL_UP);
   return TRUE;
 }
 
 }  // namespace
 
 namespace content {
 
+WebContentsView* CreateWebContentsView(WebContentsImpl* web_contents,
+                                       WebContentsViewDelegate* delegate) {
+  return new WebContentsViewGtk(web_contents, delegate);
+}
+
 WebContentsViewGtk::WebContentsViewGtk(
     WebContentsImpl* web_contents,
     content::WebContentsViewDelegate* delegate)
     : web_contents_(web_contents),
       expanded_(gtk_expanded_container_new()),
       delegate_(delegate) {
   gtk_widget_set_name(expanded_.get(), "chrome-web-contents-view");
   g_signal_connect(expanded_.get(), "size-allocate",
                    G_CALLBACK(OnSizeAllocateThunk), this);
   g_signal_connect(expanded_.get(), "child-size-request",
@@ skipping 334 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