Code cleanup and typos in trace_event [NFC]

base/trace_event/memory_dump_provider_info.h

Index: base/trace_event/memory_dump_provider_info.h
diff --git a/base/trace_event/memory_dump_provider_info.h b/base/trace_event/memory_dump_provider_info.h
index aeacea1255c7245c8901effa85163323c2377be3..9d18b82134353ae0f664b23edf5161f0770c38eb 100644
--- a/base/trace_event/memory_dump_provider_info.h
+++ b/base/trace_event/memory_dump_provider_info.h
@@ -31,7 +31,7 @@ namespace trace_event {
 // At any time, there is at most one instance of this class for each instance
 // of a given MemoryDumpProvider, but there might be several scoped_refptr
 // holding onto each of this. Specifically:
-// - In nominal conditions, there is a refptr for each registerd MDP in the
+// - In nominal conditions, there is a refptr for each registered MDP in the
 //   MDM's |dump_providers_| list.
 // - In most cases, the only refptr (in the |dump_providers_| list) is destroyed
 //   by MDM::UnregisterDumpProvider().