[Mac] Record backtrace with nsexception logging.

chrome/browser/chrome_browser_application_mac.mm

Index: chrome/browser/chrome_browser_application_mac.mm
diff --git a/chrome/browser/chrome_browser_application_mac.mm b/chrome/browser/chrome_browser_application_mac.mm
index f02ca0d51470c0f15c8460e22df9de017b4ee502..b4b91b593fc398256a831c89fb33f2e98a3c0378 100644
--- a/chrome/browser/chrome_browser_application_mac.mm
+++ b/chrome/browser/chrome_browser_application_mac.mm
@@ -6,6 +6,7 @@
 
 #import "base/auto_reset.h"
 #include "base/debug/crash_logging.h"
+#include "base/debug/stack_trace.h"
 #import "base/logging.h"
 #import "base/mac/scoped_nsexception_enabler.h"
 #import "base/memory/scoped_nsobject.h"
@@ -66,6 +67,8 @@ static IMP gOriginalInitIMP = NULL;
     std::string value = base::StringPrintf("%s reason %s",
         [aName UTF8String], [aReason UTF8String]);
     base::debug::SetCrashKeyValue(crash_keys::mac::kNSException, value);
+    base::debug::SetCrashKeyToStackTrace(crash_keys::mac::kNSExceptionTrace,
+                                         base::debug::StackTrace());
 
     // Force crash for selected exceptions to generate crash dumps.
     BOOL fatal = NO;