Nits fix on trace_event.h and child_trace_message_filter.cc

base/debug/trace_event.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Trace events are for tracking application performance.
 //
 // Events are issued against categories. Whereas LOG's
 // categories are statically defined, TRACE categories are created
 // implicitly with a string. For example:
 //   TRACE_EVENT_INSTANT0("MY_SUBSYSTEM", "SomeImportantEvent")
@@ skipping 36 matching lines @@
 // statically allocated and safe at all times, even after exit. Fetching a
 // category is protected by the TraceLog::lock_. Multiple threads initializing
 // the static variable is safe, as they will be serialized by the lock and
 // multiple calls will return the same pointer to the category.
 //
 // Then the category.enabled flag is checked. This is a volatile bool, and
 // not intended to be multithread safe. It optimizes access to AddTraceEvent
 // which is threadsafe internally via TraceLog::lock_. The enabled flag may
 // cause some threads to incorrectly call or skip calling AddTraceEvent near
 // the time of the system being enabled or disabled. This is acceptable as
-// we tollerate some data loss while the system is being enabled/disabled and
+// we tolerate some data loss while the system is being enabled/disabled and
 // because AddTraceEvent is threadsafe internally and checks the enabled state
 // again under lock.
 //
 // Without the use of these static category pointers and enabled flags all
 // trace points would carry a significant performance cost of aquiring a lock
 // and resolving the category.
 //
 // ANNOTATE_BENIGN_RACE is used to suppress the warning on the static category
 // pointers.
 
@@ skipping 416 matching lines @@
   const TraceCategory* category_;
   const char* name_;
 };
 
 }  // namespace internal
 
 }  // namespace debug
 }  // namespace base
 
 #endif  // BASE_DEBUG_TRACE_EVENT_H_