Histograms - Support histograms for Plugins, GPU

content/public/common/content_constants.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.
 
 // A handful of resource-like constants related to the Content application.
 
 #ifndef CONTENT_PUBLIC_COMMON_CONTENT_CONSTANTS_H_
 #define CONTENT_PUBLIC_COMMON_CONTENT_CONSTANTS_H_
 
 #include <stddef.h>         // For size_t
@@ skipping 28 matching lines @@
 // We have different values for "max accepted" and "max displayed" because
 // a data: URI may be legitimately massive, but the full URI would kill all
 // known operating systems if you dropped it into a UI control.
 CONTENT_EXPORT extern const size_t kMaxURLChars;
 CONTENT_EXPORT extern const size_t kMaxURLDisplayChars;
 
 extern const char kStatsFilename[];
 extern const int kStatsMaxThreads;
 extern const int kStatsMaxCounters;
 
+// Most sequence numbers are used by a renderer when responding to a browser
+// request for histogram data.  This reserved number is used when a renderer
+// sends an unprovoked update, such as after a page has been loaded.  Using
+// this reserved constant avoids any chance of confusion with a response having
+// a browser-supplied sequence number.
+CONTENT_EXPORT extern const int kHistogramSynchronizerReservedSequenceNumber;
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_CONTENT_CONSTANTS_H_