Start collecting two new WebSocket histograms.

Source/modules/websockets/WebSocketDeflater.h

 /*
  * Copyright (C) 2012 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 26 matching lines @@
 #include "wtf/Vector.h"
 
 struct z_stream_s;
 typedef z_stream_s z_stream;
 
 namespace WebCore {
 
 class WebSocketDeflater {
     WTF_MAKE_FAST_ALLOCATED;
 public:
+    // This enum is reused for histogram. When this needs to be modified, add a
+    // new enum for histogram and convert mode values into values in the new
+    // enum to keep new data consistent with old one.
     enum ContextTakeOverMode {
         DoNotTakeOverContext,
-        TakeOverContext
+        TakeOverContext,
+        ContextTakeOverModeMax,
     };
     static PassOwnPtr<WebSocketDeflater> create(int windowBits, ContextTakeOverMode = TakeOverContext);
 
     ~WebSocketDeflater();
 
     bool initialize();
     bool addBytes(const char*, size_t);
     bool finish();
     const char* data() { return m_buffer.data(); }
     size_t size() const { return m_buffer.size(); }
@@ skipping 30 matching lines @@
     explicit WebSocketInflater(int windowBits);
 
     int m_windowBits;
     Vector<char> m_buffer;
     OwnPtr<z_stream> m_stream;
 };
 
 }
 
 #endif // WebSocketDeflater_h