Record DevTools metadata events on worker threads when starting recoring tracing based Timeline

Source/core/inspector/InspectorTracingAgent.cpp

 //
 // Copyright 2014 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.
 //
 
 #include "config.h"
 
 #include "core/inspector/InspectorTracingAgent.h"
 
 #include "core/inspector/IdentifiersFactory.h"
 #include "core/inspector/InspectorClient.h"
 #include "core/inspector/InspectorState.h"
+#include "core/inspector/InspectorWorkerAgent.h"
 #include "platform/TraceEvent.h"
 
 namespace blink {
 
 namespace TracingAgentState {
 const char sessionId[] = "sessionId";
 const char tracingStartedFromProtocol[] = "tracingStartedFromProtocol";
 const char tracingStarted[] = "tracingStarted";
 }
 
 namespace {
 const char devtoolsMetadataEventCategory[] = TRACE_DISABLED_BY_DEFAULT("devtools.timeline");
 }
 
-InspectorTracingAgent::InspectorTracingAgent(InspectorClient* client)
+InspectorTracingAgent::InspectorTracingAgent(InspectorClient* client, InspectorWorkerAgent* workerAgent)
     : InspectorBaseAgent<InspectorTracingAgent>("Tracing")
     , m_layerTreeId(0)
     , m_client(client)
     , m_frontend(0)
+    , m_workerAgent(workerAgent)
 {
 }
 
 void InspectorTracingAgent::restore()
 {
     emitMetadataEvents();
 }
 
 void InspectorTracingAgent::start(ErrorString*, const String& categoryFilter, const String&, const double*)
 {
     m_state->setBoolean(TracingAgentState::tracingStartedFromProtocol, true);
     innerStart(categoryFilter, false);
 }
 
 void InspectorTracingAgent::end(ErrorString* errorString)
 {
     m_state->setBoolean(TracingAgentState::tracingStarted, false);
     m_consoleTimelines.clear();
-    m_frontend->stopped();
+    notifyTracingStopped();
 }
 
 void InspectorTracingAgent::innerStart(const String& categoryFilter, bool fromConsole)
 {
     m_state->setString(TracingAgentState::sessionId, IdentifiersFactory::createIdentifier());
     m_state->setBoolean(TracingAgentState::tracingStarted, true);
     m_client->enableTracing(categoryFilter);
     emitMetadataEvents();
     m_frontend->started(fromConsole, sessionId());
 }
 
 String InspectorTracingAgent::sessionId()
 {
     return m_state->getString(TracingAgentState::sessionId);
 }
 
 void InspectorTracingAgent::emitMetadataEvents()
 {
     if (!m_state->getBoolean(TracingAgentState::tracingStarted))
         return;
     TRACE_EVENT_INSTANT1(devtoolsMetadataEventCategory, "TracingStartedInPage", "sessionId", sessionId().utf8());
     if (m_layerTreeId)
         setLayerTreeId(m_layerTreeId);
+    m_workerAgent->setTracingSessionId(sessionId());
 }
 
 void InspectorTracingAgent::setLayerTreeId(int layerTreeId)
 {
     m_layerTreeId = layerTreeId;
     TRACE_EVENT_INSTANT2(devtoolsMetadataEventCategory, "SetLayerTreeId", "sessionId", sessionId().utf8(), "layerTreeId", m_layerTreeId);
 }
 
 void InspectorTracingAgent::consoleTimeline(const String& title)
 {
     m_consoleTimelines.append(title);
     if (m_state->getBoolean(TracingAgentState::tracingStarted))
         return;
     innerStart("-*,disabled-by-default-devtools.timeline", true);
 }
 
 void InspectorTracingAgent::consoleTimelineEnd(const String& title)
 {
     size_t index = m_consoleTimelines.find(title);
     if (index == kNotFound)
         return;
 
     m_consoleTimelines.remove(index);
     if (!m_consoleTimelines.size()
         && m_state->getBoolean(TracingAgentState::tracingStarted)
         && !m_state->getBoolean(TracingAgentState::tracingStartedFromProtocol))
-        m_frontend->stopped();
+        notifyTracingStopped();
     m_state->setBoolean(TracingAgentState::tracingStarted, false);
 }
 
+void InspectorTracingAgent::notifyTracingStopped()
+{
+    m_frontend->stopped();
+    m_workerAgent->setTracingSessionId(String());
+}
+
 void InspectorTracingAgent::setFrontend(InspectorFrontend* frontend)
 {
     m_frontend = frontend->tracing();
 }
 
 }