Add a temporary crash key to debug nib loading issues.

chrome/common/crash_keys.cc

Index: chrome/common/crash_keys.cc
diff --git a/chrome/common/crash_keys.cc b/chrome/common/crash_keys.cc
index 4ce7af6eee46dfce34a5d0e679a40aa382dc5acc..e57c9a806903ede90b843b1f7c359bd6b59f1f9a 100644
--- a/chrome/common/crash_keys.cc
+++ b/chrome/common/crash_keys.cc
@@ -89,6 +89,8 @@ const char kSendAction[] = "sendaction";
 
 const char kNSEvent[] = "nsevent";
 
+const char kToolbarNibInfo[] = "toolbar-nib-info";
+
 }  // namespace mac
 #endif
 
@@ -162,6 +164,7 @@ size_t RegisterChromeCrashKeys() {
     { mac::kNSExceptionTrace, kMediumSize },
     { mac::kSendAction, kMediumSize },
     { mac::kNSEvent, kMediumSize },
+    { mac::kToolbarNibInfo, kMediumSize },
     { mac::kZombie, kMediumSize },
     { mac::kZombieTrace, kMediumSize },
     // content/: