Move Render(View|Widget)Host and associated classes to content namespace.

content/browser/tab_contents/web_drag_dest_gtk.h

Index: content/browser/tab_contents/web_drag_dest_gtk.h
diff --git a/content/browser/tab_contents/web_drag_dest_gtk.h b/content/browser/tab_contents/web_drag_dest_gtk.h
index 23d8bcc9dd512af3082050922e131c943a023be3..779060420fdd1e12207c2d64ac390b353e64915b 100644
--- a/content/browser/tab_contents/web_drag_dest_gtk.h
+++ b/content/browser/tab_contents/web_drag_dest_gtk.h
@@ -16,10 +16,9 @@
 #include "ui/base/gtk/gtk_signal.h"
 #include "webkit/glue/webdropdata.h"
 
-class RenderViewHostImpl;
-
 namespace content {
 
+class RenderViewHostImpl;
 class WebContents;
 class WebDragDestDelegate;
 
@@ -42,7 +41,7 @@ class CONTENT_EXPORT WebDragDestGtk {
   void set_delegate(WebDragDestDelegate* delegate) { delegate_ = delegate; }
 
  private:
-  RenderViewHostImpl* GetRenderViewHost() const;
+  content::RenderViewHostImpl* GetRenderViewHost() const;
 
   // Called when a system drag crosses over the render view. As there is no drag
   // enter event, we treat it as an enter event (and not a regular motion event)