Part 1 of repairing regressions to my old clang check plugins so Nico can

chrome/common/child_thread.h

Index: chrome/common/child_thread.h
diff --git a/chrome/common/child_thread.h b/chrome/common/child_thread.h
index dbe86778679d3ccd40f44f336cdd90d5a8a926a2..4537f1ba9c84b1ea94ffdf0e611143ef1369e9c5 100644
--- a/chrome/common/child_thread.h
+++ b/chrome/common/child_thread.h
@@ -74,9 +74,7 @@ class ChildThread : public IPC::Channel::Listener,
   // Called when the process refcount is 0.
   void OnProcessFinalRelease();
 
-  virtual bool OnControlMessageReceived(const IPC::Message& msg) {
-    return false;
-  }
+  virtual bool OnControlMessageReceived(const IPC::Message& msg);
   virtual void OnAskBeforeShutdown();
   virtual void OnShutdown();