Refactor InspectorWebPerfAgent: update lifecycle management to be per Local Frame root; replace hea…

third_party/WebKit/Source/core/inspector/InspectorWebPerfAgent.h

Index: third_party/WebKit/Source/core/inspector/InspectorWebPerfAgent.h
diff --git a/third_party/WebKit/Source/core/inspector/InspectorWebPerfAgent.h b/third_party/WebKit/Source/core/inspector/InspectorWebPerfAgent.h
index f0f8ed6c185fd0eae694d20c151973f156cb97e1..b89d760d0500ae6c62679e60549c37699cc6ce52 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorWebPerfAgent.h
+++ b/third_party/WebKit/Source/core/inspector/InspectorWebPerfAgent.h
@@ -17,8 +17,37 @@ class ExecutionContext;
 class Frame;
 class LocalFrame;
 class Location;
+class Performance;
 
 // Inspector Agent for Web Performance APIs
+// The agent is maintained per local root.
+// Long task notifications are delivered to observing Performance* instances
+// (in the local frame tree) in m_webPerformanceObservers.
+//
+// Usage:
+// To create agent:
+//     - instantiate and enable the agent:
+//           inspectorWebPerfAgent = new InspectorWebPerfAgent(localFrame);
+//           inspectorWebPerfAgent->enable();
+//     - add first Performanace* instance:
+//     inspectorWebPerfAgent->addWebPerformanceObserver(performance)
+//
+// To add additional Performance* observers, within the local frame tree:
+//     inspectorWebPerfAgent->addWebPerformanceObserver(performance);
+//
+// To remove Performance* observer:
+//     inspectorWebPerfAgent->removeWebPerformanceObserver(performance);
+//
+// To delete the agent:
+//     - remove last Performance* observer
+//           inspectorWebPerfAgent->removeWebPerformanceObserver(performance);
+//     - ensure all Performance* observers have been removed:
+//           if (!inspectorWebPerfAgent->hasWebPerformanceObservers()) { ..
+//     - delete the agent:
+//           inspectorWebPerfAgent->disable();
+//           inspectorWebPerfAgent = nullptr; // depending on lifetime
+//           management
+//
 class CORE_EXPORT InspectorWebPerfAgent final
     : public GarbageCollectedFinalized<InspectorWebPerfAgent>,
       public WebThread::TaskObserver,
@@ -33,6 +62,11 @@ class CORE_EXPORT InspectorWebPerfAgent final
 
   void enable();
   void disable();
+  bool isEnabled();
+
+  void addWebPerformanceObserver(Performance*);
+  void removeWebPerformanceObserver(Performance*);
+  bool hasWebPerformanceObservers();
 
   void willExecuteScript(ExecutionContext*);
   void didExecuteScript();
@@ -49,11 +83,12 @@ class CORE_EXPORT InspectorWebPerfAgent final
  private:
   bool m_enabled;
   std::pair<String, DOMWindow*> sanitizedAttribution(
-      const HeapHashSet<Member<Location>>& frameContextLocations,
+      const HeapHashSet<Member<Frame>>& frameContexts,
       Frame* observerFrame);
 
-  Member<LocalFrame> m_localFrame;
-  HeapHashSet<Member<Location>> m_frameContextLocations;
+  Member<LocalFrame> m_localRoot;
+  HeapHashSet<Member<Frame>> m_frameContexts;
+  HeapHashSet<Member<Performance>> m_webPerformanceObservers;
 };
 
 }  // namespace blink