ServiceWorker: UMA histogram to track the size of Service Worker scripts

Source/web/WebEmbeddedWorkerImpl.cpp

 /*
  * Copyright (C) 2013 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 32 matching lines @@
 #include "core/workers/WorkerInspectorProxy.h"
 #include "core/workers/WorkerLoaderProxy.h"
 #include "core/workers/WorkerScriptLoader.h"
 #include "core/workers/WorkerScriptLoaderClient.h"
 #include "core/workers/WorkerThreadStartupData.h"
 #include "modules/serviceworkers/ServiceWorkerThread.h"
 #include "platform/NotImplemented.h"
 #include "platform/SharedBuffer.h"
 #include "platform/heap/Handle.h"
 #include "platform/network/ContentSecurityPolicyParsers.h"
+#include "public/platform/Platform.h"
 #include "public/platform/WebURLRequest.h"
 #include "public/web/WebDevToolsAgent.h"
 #include "public/web/WebServiceWorkerContextClient.h"
 #include "public/web/WebServiceWorkerNetworkProvider.h"
 #include "public/web/WebSettings.h"
 #include "public/web/WebView.h"
 #include "public/web/WebWorkerPermissionClientProxy.h"
 #include "web/ServiceWorkerGlobalScopeClientImpl.h"
 #include "web/ServiceWorkerGlobalScopeProxy.h"
 #include "web/WebDataSourceImpl.h"
@@ skipping 310 matching lines @@
     if (m_askedToTerminate)
         return;
 
     if (m_mainScriptLoader->failed()) {
         m_mainScriptLoader.clear();
         // This may delete 'this'.
         m_workerContextClient->workerContextFailedToStart();
         return;
     }
 
+    Platform::current()->histogramCustomCounts("ServiceWorker.ScriptSize", m_mainScriptLoader->script().length(), 1000, 5000000, 50);
+
     if (m_pauseAfterDownloadState == DoPauseAfterDownload) {
         m_pauseAfterDownloadState = IsPausedAfterDownload;
         m_workerContextClient->didPauseAfterDownload();
         return;
     }
     startWorkerThread();
 }
 
 void WebEmbeddedWorkerImpl::startWorkerThread()
 {
@@ skipping 25 matching lines @@
     m_mainScriptLoader.clear();
 
     m_workerGlobalScopeProxy = ServiceWorkerGlobalScopeProxy::create(*this, *document, *m_workerContextClient);
     m_loaderProxy = LoaderProxy::create(*this);
     m_workerThread = ServiceWorkerThread::create(*m_loaderProxy, *m_workerGlobalScopeProxy, startupData.release());
     m_workerThread->start();
     m_workerInspectorProxy->workerThreadCreated(document, m_workerThread.get(), scriptURL);
 }
 
 } // namespace blink