Split trace messages into chunks based on size, not event count

content/browser/devtools/devtools_tracing_handler.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 "content/browser/devtools/devtools_tracing_handler.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 74 matching lines @@
     DCHECK(ok);
     std::string buffer;
     for (size_t i = 0; i < list->GetSize(); ++i) {
       std::string item;
       base::Value* item_value;
       list->Get(i, &item_value);
       base::JSONWriter::Write(item_value, &item);
       if (buffer.size())
         buffer.append(",");
       buffer.append(item);
-      if (i % 1000 == 0) {
+      const size_t kMessageSizeThreshold = 1024 * 1024;
+      if (buffer.size() > kMessageSizeThreshold) {
         OnTraceDataCollected(buffer);
         buffer.clear();
       }
     }
     if (buffer.size())
       OnTraceDataCollected(buffer);
   }
 
   SendNotification(devtools::Tracing::tracingComplete::kName, NULL);
 }
@@ skipping 136 matching lines @@
        it != category_set.end(); ++it) {
     category_list->AppendString(*it);
   }
 
   response->Set(devtools::Tracing::getCategories::kResponseCategories,
                 category_list);
   SendAsyncResponse(command->SuccessResponse(response));
 }
 
 }  // namespace content