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

third_party/WebKit/Source/core/timing/Performance.cpp

Index: third_party/WebKit/Source/core/timing/Performance.cpp
diff --git a/third_party/WebKit/Source/core/timing/Performance.cpp b/third_party/WebKit/Source/core/timing/Performance.cpp
index abfaffecadc78123316515dd844a43b4598daa68..f420f6e8fcae5a0d1a9539edb6de6c8947c79fce 100644
--- a/third_party/WebKit/Source/core/timing/Performance.cpp
+++ b/third_party/WebKit/Source/core/timing/Performance.cpp
@@ -35,7 +35,6 @@
 #include "bindings/core/v8/V8ObjectBuilder.h"
 #include "core/dom/Document.h"
 #include "core/frame/LocalFrame.h"
-#include "core/inspector/InspectedFrames.h"
 #include "core/inspector/InspectorWebPerfAgent.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/origin_trials/OriginTrials.h"
@@ -59,9 +58,17 @@ static double toTimeOrigin(LocalFrame* frame) {
 }
 
 Performance::Performance(LocalFrame* frame)
-    : PerformanceBase(toTimeOrigin(frame)), DOMWindowProperty(frame) {}
-
-Performance::~Performance() {}
+    : PerformanceBase(toTimeOrigin(frame)),
+      DOMWindowProperty(frame),
+      m_observingLongTasks(false) {}
+
+Performance::~Performance() {
+  LocalFrame* localRoot = frame()->localFrameRoot();
+  if (m_observingLongTasks && localRoot && localRoot->inspectorWebPerfAgent()) {

[caseq, 2016/10/26 21:19:41]

We're supposed to always have the agent for a local root, right?

[panicker, 2016/10/27 23:06:53]

Yeah, currently.
Though your other suggestion was to keep it only when needed (delete when noone
is observering, re-create when observer registers) right?

[panicker, 2016/10/28 00:09:24]

Done.

+    m_observingLongTasks = false;
+    localRoot->disableInspectorWebPerfAgent();
+  }
+}
 
 ExecutionContext* Performance::getExecutionContext() const {
   if (!frame())
@@ -88,16 +95,21 @@ PerformanceTiming* Performance::timing() const {
 }
 
 void Performance::updateLongTaskInstrumentation() {
-  if (hasObserverFor(PerformanceEntry::LongTask) && !m_longTaskInspectorAgent) {
-    if (!frame() || !frame()->document() ||
-        !OriginTrials::longTaskObserverEnabled(frame()->document()))
-      return;
-    m_longTaskInspectorAgent = new InspectorWebPerfAgent(frame());
-    m_longTaskInspectorAgent->enable();
-  } else if (!hasObserverFor(PerformanceEntry::LongTask) &&
-             m_longTaskInspectorAgent) {
-    m_longTaskInspectorAgent->disable();
-    m_longTaskInspectorAgent = nullptr;
+  DCHECK(frame());
+  if (!frame()->document() ||
+      !OriginTrials::longTaskObserverEnabled(frame()->document()))
+    return;
+  LocalFrame* localRoot = frame()->localFrameRoot();
+  DCHECK(localRoot);
+  DCHECK(localRoot->inspectorWebPerfAgent());
+
+  if (!m_observingLongTasks && hasObserverFor(PerformanceEntry::LongTask)) {
+    m_observingLongTasks = true;
+    localRoot->enableInspectorWebPerfAgent();
+  } else if (m_observingLongTasks &&
+             !hasObserverFor(PerformanceEntry::LongTask)) {
+    m_observingLongTasks = false;
+    localRoot->disableInspectorWebPerfAgent();
   }
 }
 
@@ -108,10 +120,13 @@ ScriptValue Performance::toJSONForBinding(ScriptState* scriptState) const {
   return result.scriptValue();
 }
 
+bool Performance::observeringLongTasks() {
+  return m_observingLongTasks;
+}
+
 DEFINE_TRACE(Performance) {
   visitor->trace(m_navigation);
   visitor->trace(m_timing);
-  visitor->trace(m_longTaskInspectorAgent);
   DOMWindowProperty::trace(visitor);
   PerformanceBase::trace(visitor);
 }