Add a factory function to create WebContentsView implementations.

content/browser/web_contents/web_contents_view_mac.mm

Index: content/browser/web_contents/web_contents_view_mac.mm
===================================================================
--- content/browser/web_contents/web_contents_view_mac.mm	(revision 137865)
+++ content/browser/web_contents/web_contents_view_mac.mm	(working copy)
@@ -57,10 +57,9 @@
 - (void)viewDidBecomeFirstResponder:(NSNotification*)notification;
 @end
 
-namespace web_contents_view_mac {
-content::WebContentsView* CreateWebContentsView(
-    WebContentsImpl* web_contents,
-    content::WebContentsViewDelegate* delegate) {
+namespace content {
+WebContentsView* CreateWebContentsView(WebContentsImpl* web_contents,
+                                       WebContentsViewDelegate* delegate) {
   return new WebContentsViewMac(web_contents, delegate);
 }
 }