1 files changed, 12 insertions, 0 deletions
diff --git a/content/browser/renderer_host/render_view_host.h b/content/browser/renderer_host/render_view_host.h
index 0304ec9..88dac2a 100644
--- a/content/browser/renderer_host/render_view_host.h
+++ b/content/browser/renderer_host/render_view_host.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
 #include "base/process_util.h"
 #include "chrome/browser/ui/find_bar/find_bar_controller.h"
 #include "chrome/common/content_settings_types.h"
@@ -32,6 +33,7 @@ class FilePath;
 class GURL;
 class ListValue;
 class RenderViewHostDelegate;
+class RenderViewHostObserver;
 class SessionStorageNamespace;
 class SiteInstance;
 class SkBitmap;
@@ -499,6 +501,13 @@ class RenderViewHost : public RenderWidgetHost {
                         GURL* url);
 
  protected:
+  friend class RenderViewHostObserver;
+
+  // Add and remove observers for filtering IPC messages.  Clients must be sure
+  // to remove the observer before they go away.
+  void AddObserver(RenderViewHostObserver* observer);
+  void RemoveObserver(RenderViewHostObserver* observer);
+
   // RenderWidgetHost protected overrides.
   virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                                       bool* is_keyboard_shortcut);
@@ -682,6 +691,9 @@ class RenderViewHost : public RenderWidgetHost {
   // The enabled/disabled states of various commands.
   std::map<RenderViewCommand, CommandState> command_states_;
 
+  // A list of observers that filter messages.  Weak references.
+  ObserverList<RenderViewHostObserver> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderViewHost);
 };