Code cleanup and typos in trace_event [NFC]

base/trace_event/memory_tracing_observer.cc

 // Copyright 2017 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.
 
 #include "base/trace_event/memory_tracing_observer.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_event_argument.h"
 
@@ skipping 13 matching lines @@
   return enabled;
 }
 
 };  // namespace
 
 MemoryTracingObserver::MemoryTracingObserver(
     TraceLog* trace_log,
     MemoryDumpManager* memory_dump_manager)
     : memory_dump_manager_(memory_dump_manager), trace_log_(trace_log) {
   // If tracing was enabled before initializing MemoryDumpManager, we missed the
-  // OnTraceLogEnabled() event. Synthetize it so we can late-join the party.
+  // OnTraceLogEnabled() event. Synthesize it so we can late-join the party.
   // IsEnabled is called before adding observer to avoid calling
   // OnTraceLogEnabled twice.
   bool is_tracing_already_enabled = trace_log_->IsEnabled();
   trace_log_->AddEnabledStateObserver(this);
   if (is_tracing_already_enabled)
     OnTraceLogEnabled();
 }
 
 MemoryTracingObserver::~MemoryTracingObserver() {
   trace_log_->RemoveEnabledStateObserver(this);
@@ skipping 61 matching lines @@
 
 bool MemoryTracingObserver::IsDumpModeAllowed(
     MemoryDumpLevelOfDetail dump_mode) const {
   if (!memory_dump_config_)
     return false;
   return memory_dump_config_->allowed_dump_modes.count(dump_mode) != 0;
 }
 
 }  // namespace trace_event
 }  // namespace base