Split up leak detector into two stages for better leak reporting.

third_party/WebKit/Source/web/WebLeakDetector.cpp

Index: third_party/WebKit/Source/web/WebLeakDetector.cpp
diff --git a/third_party/WebKit/Source/web/WebLeakDetector.cpp b/third_party/WebKit/Source/web/WebLeakDetector.cpp
index e1ddecbab86bf329b6cd9c60d7956be2f3b50bd0..1c1c7952c761575948ea7db8dabd925ab9c8b021 100644
--- a/third_party/WebKit/Source/web/WebLeakDetector.cpp
+++ b/third_party/WebKit/Source/web/WebLeakDetector.cpp
@@ -59,6 +59,9 @@ public:
         , m_delayedGCAndReportTimer(this, &WebLeakDetectorImpl::delayedGCAndReport)
         , m_delayedReportTimer(this, &WebLeakDetectorImpl::delayedReport)
         , m_numberOfGCNeeded(0)
+#if ENABLE(ASSERT)
+        , m_haveReported(false)
+#endif
     {
         ASSERT(m_client);
     }
@@ -67,6 +70,9 @@ public:
 
     void collectGarbageAndGetDOMCounts(WebLocalFrame*) override;
 
+    void prepareForLeakDetection(WebLocalFrame*) override;
+    void collectGarbageAndReport() override;
+
 private:
     void delayedGCAndReport(Timer<WebLeakDetectorImpl>*);
     void delayedReport(Timer<WebLeakDetectorImpl>*);
@@ -75,9 +81,12 @@ private:
     Timer<WebLeakDetectorImpl> m_delayedGCAndReportTimer;
     Timer<WebLeakDetectorImpl> m_delayedReportTimer;
     int m_numberOfGCNeeded;
+#if ENABLE(ASSERT)
+    bool m_haveReported;
+#endif
 };
 
-void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)
+void WebLeakDetectorImpl::prepareForLeakDetection(WebLocalFrame* frame)
 {
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     v8::HandleScope handleScope(isolate);
@@ -99,6 +108,18 @@ void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)
     }
 
     // FIXME: HTML5 Notification should be closed because notification affects the result of number of DOM objects.
+}
+
+void WebLeakDetectorImpl::collectGarbageAndReport()
+{
+#if ENABLE(ASSERT)
+    // Repeated uses are not supported.
+    ASSERT(!m_haveReported);
+    m_haveReported = true;
+#endif
+
+    v8::Isolate* isolate = v8::Isolate::GetCurrent();
+    v8::HandleScope handleScope(isolate);
 
     V8GCController::collectAllGarbageForTesting(isolate);
     // Note: Oilpan precise GC is scheduled at the end of the event loop.
@@ -113,6 +134,12 @@ void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)
     m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
 }
 
+void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)
+{
+    prepareForLeakDetection(frame);
+    collectGarbageAndReport();
+}
+
 void WebLeakDetectorImpl::delayedGCAndReport(Timer<WebLeakDetectorImpl>*)
 {
     // We do a second and third GC here to address flakiness