Allow MessageFilters to restrict listening to specific message classes

content/public/browser/browser_message_filter.h

Index: content/public/browser/browser_message_filter.h
diff --git a/content/public/browser/browser_message_filter.h b/content/public/browser/browser_message_filter.h
index ad1f0693790b2abb0177ffe92433b49b9861fada..5505c1c7f52c12217603108c3a8102ccc749a67c 100644
--- a/content/public/browser/browser_message_filter.h
+++ b/content/public/browser/browser_message_filter.h
@@ -29,7 +29,9 @@ class CONTENT_EXPORT BrowserMessageFilter
           BrowserMessageFilter, BrowserMessageFilterTraits>,
       public IPC::Sender {
  public:
-  BrowserMessageFilter();
+  explicit BrowserMessageFilter(uint32 message_class_to_filter);
+  BrowserMessageFilter(const uint32* message_classes_to_filter,
+                       size_t num_message_classes_to_filter);
 
   // These match the corresponding IPC::ChannelProxy::MessageFilter methods and
   // are always called on the IO thread.
@@ -91,6 +93,10 @@ class CONTENT_EXPORT BrowserMessageFilter
   // Can be called on any thread.
   virtual void BadMessageReceived();
 
+  const std::vector<uint32>& message_classes_to_filter() const {
+    return message_classes_to_filter_;
+  }
+
  protected:
   virtual ~BrowserMessageFilter();
 
@@ -117,6 +123,8 @@ class CONTENT_EXPORT BrowserMessageFilter
   IPC::Channel* channel_;
   base::ProcessId peer_pid_;
 
+  std::vector<uint32> message_classes_to_filter_;
+
 #if defined(OS_WIN)
   base::Lock peer_handle_lock_;
   base::ProcessHandle peer_handle_;