Increase number of bits for trace buffer chunk index

base/trace_event/trace_buffer.h

 // Copyright 2015 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_TRACE_BUFFER_H_
 #define BASE_TRACE_EVENT_TRACE_BUFFER_H_
 
 #include "base/base_export.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_impl.h"
@@ skipping 22 matching lines @@
   }
   const TraceEvent* GetEventAt(size_t index) const {
     DCHECK(index < size());
     return &chunk_[index];
   }
 
   scoped_ptr<TraceBufferChunk> Clone() const;
 
   void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead);
 
+  // These values must be kept consistent with the numbers of bits of
+  // chunk_index and event_index fields in TraceEventHandle
+  // (in trace_event_impl.h).
+  static const size_t kMaxChunkIndex = (1u << 26) - 1;
   static const size_t kTraceBufferChunkSize = 64;
 
  private:
   size_t next_free_;
   scoped_ptr<TraceEventMemoryOverhead> cached_overhead_estimate_;
   TraceEvent chunk_[kTraceBufferChunkSize];
   uint32 seq_;
 };
 
 // TraceBuffer holds the events as they are collected.
@@ skipping 64 matching lines @@
 
  private:
   OutputCallback output_callback_;
   bool append_comma_;
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_TRACE_BUFFER_H_