Add UMA to understand the typical total size of ServiceWorker script [1/2 blink]

Source/core/workers/WorkerGlobalScope.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009, 2011 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 250 matching lines @@
         scriptLoader->setRequestContext(blink::WebURLRequest::RequestContextScript);
         scriptLoader->loadSynchronously(executionContext, completeURL, AllowCrossOriginRequests);
 
         // If the fetching attempt failed, throw a NetworkError exception and abort all these steps.
         if (scriptLoader->failed()) {
             exceptionState.throwDOMException(NetworkError, "The script at '" + completeURL.elidedString() + "' failed to load.");
             return;
         }
 
         InspectorInstrumentation::scriptImported(&executionContext, scriptLoader->identifier(), scriptLoader->script());
+        scriptLoaded(scriptLoader->script().length(), scriptLoader->cachedMetadata() ? scriptLoader->cachedMetadata()->size() : 0);
 
         RefPtrWillBeRawPtr<ErrorEvent> errorEvent = nullptr;
         OwnPtr<Vector<char>> cachedMetaData(scriptLoader->releaseCachedMetadata());
         OwnPtr<CachedMetadataHandler> handler(createWorkerScriptCachedMetadataHandler(completeURL, cachedMetaData.get()));
         m_script->evaluate(ScriptSourceCode(scriptLoader->script(), scriptLoader->responseURL()), &errorEvent, handler.get(), m_v8CacheOptions);
         if (errorEvent) {
             m_script->rethrowExceptionFromImportedScript(errorEvent.release(), exceptionState);
             return;
         }
     }
@@ skipping 104 matching lines @@
     visitor->trace(m_timers);
     visitor->trace(m_messageStorage);
     visitor->trace(m_pendingMessages);
     HeapSupplementable<WorkerGlobalScope>::trace(visitor);
 #endif
     ExecutionContext::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace blink