Make IPC::Channel::Listener:OnMessageReceived have a return value indicating ...

chrome/browser/plugin_process_host.cc

Index: chrome/browser/plugin_process_host.cc
===================================================================
--- chrome/browser/plugin_process_host.cc	(revision 70108)
+++ chrome/browser/plugin_process_host.cc	(working copy)
@@ -298,7 +298,8 @@
   }
 }
 
-void PluginProcessHost::OnMessageReceived(const IPC::Message& msg) {
+bool PluginProcessHost::OnMessageReceived(const IPC::Message& msg) {
+  bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PluginProcessHost, msg)
     IPC_MESSAGE_HANDLER(PluginProcessHostMsg_ChannelCreated, OnChannelCreated)
     IPC_MESSAGE_HANDLER(PluginProcessHostMsg_GetPluginFinderUrl,
@@ -327,8 +328,11 @@
     IPC_MESSAGE_HANDLER(PluginProcessHostMsg_PluginSetCursorVisibility,
                         OnPluginSetCursorVisibility)
 #endif
-    IPC_MESSAGE_UNHANDLED_ERROR()
+    IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
+
+  DCHECK(handled);
+  return handled;
 }
 
 void PluginProcessHost::OnChannelConnected(int32 peer_pid) {