Add some instrumentation to BrowserProcessImpl.

chrome/browser/browser_process_impl.h

Index: chrome/browser/browser_process_impl.h
diff --git a/chrome/browser/browser_process_impl.h b/chrome/browser/browser_process_impl.h
index 32be9395960e90e71b06b5643fa9c930773bdb51..c063305f6a3f5613372f9b1f9bdb49d01998f9d3 100644
--- a/chrome/browser/browser_process_impl.h
+++ b/chrome/browser/browser_process_impl.h
@@ -14,6 +14,7 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/debug/stack_trace.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/threading/non_thread_safe.h"
@@ -272,6 +273,10 @@ class BrowserProcessImpl : public BrowserProcess,
 
   scoped_refptr<AudioManager> audio_manager_;
 
+  // TODO(eroman): Remove this when done debugging 113031. This tracks
+  // the callstack which released the final module reference count.
+  base::debug::StackTrace release_last_reference_callstack_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserProcessImpl);
 };