Start collecting two new WebSocket histograms.

Source/modules/websockets/WebSocketHandshake.cpp

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. 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.
@@ skipping 21 matching lines @@
 #include "config.h"
 
 #include "modules/websockets/WebSocket.h"
 #include "modules/websockets/WebSocketHandshake.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ScriptExecutionContext.h"
 #include "core/inspector/ScriptCallStack.h"
 #include "core/loader/CookieJar.h"
 #include "core/platform/Cookie.h"
+#include "core/platform/HistogramSupport.h"
 #include "core/platform/KURL.h"
 #include "core/platform/Logging.h"
 #include "core/platform/network/HTTPHeaderMap.h"
 #include "core/platform/network/HTTPParsers.h"
 #include "weborigin/SecurityOrigin.h"
 #include "wtf/CryptographicallyRandomNumber.h"
 #include "wtf/MD5.h"
 #include "wtf/SHA1.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/StringExtras.h"
@@ skipping 72 matching lines @@
     , m_secure(m_url.protocolIs("wss"))
     , m_context(context)
     , m_mode(Incomplete)
 {
     m_secWebSocketKey = generateSecWebSocketKey();
     m_expectedAccept = getExpectedWebSocketAccept(m_secWebSocketKey);
 }
 
 WebSocketHandshake::~WebSocketHandshake()
 {
+    HistogramSupport::histogramEnumeration("WebCore.WebSocket.HandshakeResult", m_mode, WebSocketHandshake::ModeMax);
 }
 
 const KURL& WebSocketHandshake::url() const
 {
     return m_url;
 }
 
 void WebSocketHandshake::setURL(const KURL& url)
 {
     m_url = url.copy();
@@ skipping 120 matching lines @@
     const String extensionValue = m_extensionDispatcher.createHeaderValue();
     if (extensionValue.length())
         request->addHeaderField("Sec-WebSocket-Extensions", extensionValue);
 
     // Add a User-Agent header.
     request->addHeaderField("User-Agent", m_context->userAgent(m_context->url()));
 
     return request.release();
 }
 
 void WebSocketHandshake::reset()

[yhirano, 2013/05/20 09:44:02]

(optional) Adding a comment (here or at the header) can be fine, such as:
  A call of this function on the established handshake will affect a histogram.

[tyoshino (SeeGerritForStatus), 2013/05/20 09:57:13]

Good catch. Done

 {
     m_mode = Incomplete;
     m_extensionDispatcher.reset();
 }
 
 void WebSocketHandshake::clearScriptExecutionContext()
 {
     m_context = 0;
 }
 
@@ skipping 260 matching lines @@
         m_clientProtocol.split(String(WebSocket::subProtocolSeperator()), result);
         if (!result.contains(serverWebSocketProtocol)) {
             m_failureReason = "Error during WebSocket handshake: Sec-WebSocket-Protocol mismatch";
             return false;
         }
     }
     return true;
 }
 
 } // namespace WebCore