[spelling] existance to existence

base/metrics/sample_vector.cc

 // Copyright (c) 2012 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/metrics/sample_vector.h"
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/persistent_memory_allocator.h"
@@ skipping 254 matching lines @@
   if (subtle::NoBarrier_Load(&counts_) == 0) {
     AutoLock lock(counts_lock.Get());
     if (subtle::NoBarrier_Load(&counts_) == 0) {
       // Create the actual counts storage while the above lock is acquired.
       HistogramBase::Count* counts = CreateCountsStorageWhileLocked();
       DCHECK(counts);
 
       // Point |counts_| to the newly created storage. This is done while
       // locked to prevent possible concurrent calls to CreateCountsStorage
       // but, between that call and here, other threads could notice the
-      // existance of the storage and race with this to set_counts(). That's
+      // existence of the storage and race with this to set_counts(). That's
       // okay because (a) it's atomic and (b) it always writes the same value.
       set_counts(counts);
     }
   }
 
   // Move any single-sample into the newly mounted storage.
   MoveSingleSampleToCounts();
 }
 
 SampleVector::SampleVector(const BucketRanges* bucket_ranges)
@@ skipping 130 matching lines @@
     return;
 
   while (index_ < counts_size_) {
     if (subtle::NoBarrier_Load(&counts_[index_]) != 0)
       return;
     index_++;
   }
 }
 
 }  // namespace base