[Mac] Add field trial tuples to breakpad crash reports.

chrome/common/child_process_logging.h

 // 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.
 
 #ifndef CHROME_COMMON_CHILD_PROCESS_LOGGING_H_
 #define CHROME_COMMON_CHILD_PROCESS_LOGGING_H_
 #pragma once
 
 #include <set>
 #include <string>
@@ skipping 13 matching lines @@
 // The maximum number of active extensions we will report.
 // Also used in chrome/app, but we define it here to avoid a common->app
 // dependency.
 static const int kMaxReportedActiveExtensions = 10;
 
 // The maximum number of experiment chunks we will report.
 // Also used in chrome/app, but we define it here to avoid a common->app
 // dependency.
 static const int kMaxReportedExperimentChunks = 15;
 
+// The maximum size of an experiment chunk. This size was picked to be
+// consistent between platforms and the value was chosen from the Windows
+// limit of google_breakpad::CustomInfoEntry::kValueMaxLength.
+static const size_t kMaxExperimentChunkSize = 64;
+
 // The maximum number of prn-info-* records.
 static const size_t kMaxReportedPrinterRecords = 4;
 
 // The maximum number of command line switches to include in the crash
 // report's metadata. Note that the mini-dump itself will also contain the
 // (original) command line arguments within the PEB.
 // Also used in chrome/app, but we define it here to avoid a common->app
 // dependency.
 static const size_t kMaxSwitches = 15;
 
@@ skipping 112 matching lines @@
 
 extern const int kMaxNumCrashURLChunks;
 extern const int kMaxNumURLChunkValueLength;
 extern const char *kUrlChunkFormatStr;
 
 }  // namespace child_process_logging
 
 #endif  // defined(OS_MACOSX)
 
 #endif  // CHROME_COMMON_CHILD_PROCESS_LOGGING_H_