DevTools: add Tracing agent on back-end

Source/core/inspector/InspectorTimelineAgent.cpp

Index: Source/core/inspector/InspectorTimelineAgent.cpp
diff --git a/Source/core/inspector/InspectorTimelineAgent.cpp b/Source/core/inspector/InspectorTimelineAgent.cpp
index c30db88f7f3835224baeeb206736f8dd04841038..5e10162ccf1bd01e303107dcc89ef7824ae58152 100644
--- a/Source/core/inspector/InspectorTimelineAgent.cpp
+++ b/Source/core/inspector/InspectorTimelineAgent.cpp
@@ -73,7 +73,6 @@ static const char includeCounters[] = "includeCounters";
 static const char includeGPUEvents[] = "includeGPUEvents";
 static const char bufferEvents[] = "bufferEvents";
 static const char liveEvents[] = "liveEvents";
-static const char traceEventCategoryFilter[] = "traceEventCategoryFilter";
 }
 
 // Must be kept in sync with WebInspector.TimelineModel.RecordType in TimelineModel.js
@@ -300,10 +299,9 @@ void InspectorTimelineAgent::restore()
     }
 }
 
-void InspectorTimelineAgent::enable(ErrorString*, const String* traceEventCategoryFilter)
+void InspectorTimelineAgent::enable(ErrorString*)
 {
     m_state->setBoolean(TimelineAgentState::enabled, true);
-    m_state->setString(TimelineAgentState::traceEventCategoryFilter, traceEventCategoryFilter ? *traceEventCategoryFilter : "");
 }
 
 void InspectorTimelineAgent::disable(ErrorString*)
@@ -357,13 +355,6 @@ void InspectorTimelineAgent::innerStart()
     if (m_overlay)
         m_overlay->startedRecordingProfile();
     m_state->setBoolean(TimelineAgentState::started, true);
-    String traceEventCategoryFilter = m_state->getString(TimelineAgentState::traceEventCategoryFilter);
-    if (!traceEventCategoryFilter.isEmpty()) {
-        m_client->enableTracing(traceEventCategoryFilter);
-        m_disableTracingOnStop = true;
-    } else {
-        m_disableTracingOnStop = false;
-    }
     m_instrumentingAgents->setInspectorTimelineAgent(this);
     ScriptGCEvent::addEventListener(this);
     if (m_client) {
@@ -418,11 +409,6 @@ void InspectorTimelineAgent::innerStop(bool fromConsole)
         if (m_state->getBoolean(TimelineAgentState::includeGPUEvents))
             m_client->stopGPUEventsRecording();
     }
-    // If we have enabled tracing, disable it now.
-    if (m_disableTracingOnStop) {
-        m_client->disableTracing();
-        m_disableTracingOnStop = false;
-    }
     m_instrumentingAgents->setInspectorTimelineAgent(0);
     ScriptGCEvent::removeEventListener(this);
 
@@ -1214,7 +1200,6 @@ InspectorTimelineAgent::InspectorTimelineAgent(InspectorPageAgent* pageAgent, In
     , m_styleRecalcElementCounter(0)
     , m_mayEmitFirstPaint(false)
     , m_lastProgressTimestamp(0)
-    , m_disableTracingOnStop(false)
 {
 }