[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.
+static const int kMaxExperimentChunkSize = 64;

[Scott Hess - ex-Googler, 2012/06/27 00:32:41]

Is the plan to share the chunking with other platforms?  Because I think that
OSX Breakpad's limit per value is 256 (or perhaps 255).

If you aren't going to share with other platforms, I think it would be better to
treat the chunking as an implementation detail for the OSX code doing the
storage, since it's not really specific to the location where it's at.

[MAD, 2012/06/28 13:03:38]

Please add a comment explaining why we kept 64.

[Alexei Svitkine (slow), 2012/06/28 15:01:32]

Done.

+
 // 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_