Make IPC::Logging register to watch for message loop destruction.

chrome/common/ipc_logging.cc

Index: chrome/common/ipc_logging.cc
===================================================================
--- chrome/common/ipc_logging.cc	(revision 10364)
+++ chrome/common/ipc_logging.cc	(working copy)
@@ -96,10 +96,11 @@
     enabled_ = true;
   SetLoggerFunctions(g_log_function_mapping);
 #endif
+
+  MessageLoop::current()->AddDestructionObserver(this);
 }
 
 Logging::~Logging() {
-  watcher_.StopWatching();
 }
 
 Logging* Logging::current() {
@@ -117,6 +118,10 @@
   RegisterWaitForEvent(!enabled_);
 }
 
+void Logging::WillDestroyCurrentMessageLoop() {
+  watcher_.StopWatching();
+}
+
 void Logging::SetLoggerFunctions(LogFunction *functions) {
   log_function_mapping_ = functions;
 }