Code cleanup and typos in trace_event [NFC]

base/trace_event/memory_peak_detector.h

 // 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.
 
 #ifndef BASE_TRACE_EVENT_MEMORY_PEAK_DETECTOR_H_
 #define BASE_TRACE_EVENT_MEMORY_PEAK_DETECTOR_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 
 namespace base {
 
 class SequencedTaskRunner;
 
 namespace trace_event {
 
 struct MemoryDumpProviderInfo;
 
 // Detects temporally local memory peaks. Peak detection is based on
 // continuously querying memory usage using MemoryDumpprovider(s) that support
 // fast polling (e.g., ProcessMetricsDumpProvider which under the hoods reads
-// /proc/PID/statm on Linux) and using a cobination of:
+// /proc/PID/statm on Linux) and using a combination of:
 // - An static threshold (currently 1% of total system memory).
 // - Sliding window stddev analysis.
 // Design doc: https://goo.gl/0kOU4A .
 // This class is NOT thread-safe, the caller has to ensure linearization of
 // the calls to the public methods. In any case, the public methods do NOT have
 // to be called from the |task_runner| on which the polling tasks run.
 class BASE_EXPORT MemoryPeakDetector {
  public:
   using OnPeakDetectedCallback = RepeatingClosure;
   using DumpProvidersList = std::vector<scoped_refptr<MemoryDumpProviderInfo>>;
@@ skipping 135 matching lines @@
   uint32_t samples_index_;
   uint32_t poll_tasks_count_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryPeakDetector);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_PEAK_DETECTOR_H_