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

chrome/profile_import/profile_import_thread.cc

Index: chrome/profile_import/profile_import_thread.cc
===================================================================
--- chrome/profile_import/profile_import_thread.cc	(revision 70108)
+++ chrome/profile_import/profile_import_thread.cc	(working copy)
@@ -34,7 +34,8 @@
 
 ProfileImportThread::~ProfileImportThread() {}
 
-void ProfileImportThread::OnControlMessageReceived(const IPC::Message& msg) {
+bool ProfileImportThread::OnControlMessageReceived(const IPC::Message& msg) {
+  bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ProfileImportThread, msg)
     IPC_MESSAGE_HANDLER(ProfileImportProcessMsg_StartImport,
                         OnImportStart)
@@ -42,7 +43,9 @@
                         OnImportCancel)
     IPC_MESSAGE_HANDLER(ProfileImportProcessMsg_ReportImportItemFinished,
                         OnImportItemFinished)
+    IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
+  return handled;
 }
 
 void ProfileImportThread::OnImportStart(