[Mac] Additional crash logging for -sendEvent: crash.

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 93ea7b0d87902bcda35948c84f836e4219e22b65..2ce5ea8230e98f5d3881f7474a3ea64efcfc010d 100644
--- a/chrome/browser/chrome_browser_application_mac.mm
+++ b/chrome/browser/chrome_browser_application_mac.mm
@@ -431,6 +431,12 @@ void SwizzleInit() {
 }
 
 - (void)sendEvent:(NSEvent*)event {
+  // TODO(shess): Squirrel away some info to direct debugging.
+  // Current hypothesis is that it's a keyboard accelerator.
+  // http://crbug.com/154483
+  static NSString* const kSendEventKey = @"sendevent";
+  base::mac::ScopedCrashKey key(kSendEventKey, [event description]);
+
   base::mac::ScopedSendingEvent sendingEventScoper;
   for (id<CrApplicationEventHookProtocol> handler in eventHooks_.get()) {
     [handler hookForEvent:event];