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..17cc3978090aaaa3311b0b7995ce6bf1e2a49141 100644
--- a/third_party/WebKit/Source/web/WebLeakDetector.cpp
+++ b/third_party/WebKit/Source/web/WebLeakDetector.cpp
@@ -59,6 +59,7 @@ public:
         , m_delayedGCAndReportTimer(this, &WebLeakDetectorImpl::delayedGCAndReport)
         , m_delayedReportTimer(this, &WebLeakDetectorImpl::delayedReport)
         , m_numberOfGCNeeded(0)
+        , m_delayFinalGarbageCollection(false)
     {
         ASSERT(m_client);
     }
@@ -67,6 +68,9 @@ public:
 
     void collectGarbageAndGetDOMCounts(WebLocalFrame*) override;
 
+    void delayFinalGarbageCollection() override { m_delayFinalGarbageCollection = true; }
+    void collectFinalGarbage() override;
+
 private:
     void delayedGCAndReport(Timer<WebLeakDetectorImpl>*);
     void delayedReport(Timer<WebLeakDetectorImpl>*);
@@ -75,8 +79,21 @@ private:
     Timer<WebLeakDetectorImpl> m_delayedGCAndReportTimer;
     Timer<WebLeakDetectorImpl> m_delayedReportTimer;
     int m_numberOfGCNeeded;
+    bool m_delayFinalGarbageCollection;
 };
 
+void WebLeakDetectorImpl::collectFinalGarbage()
+{
+    ASSERT(m_delayFinalGarbageCollection);
+
+    // Task queue may contain delayed object destruction tasks.
+    // This method is called from navigation hook inside FrameLoader,
+    // so previous document is still held by the loader until the next event loop.
+    // Complete all pending tasks before proceeding to gc.
+    m_numberOfGCNeeded = 2;
+    m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
+}
+
 void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)

[haraken, 2015/11/24 23:54:51]

Instead of introducing a notion of "delayed", I'd split this method into two
e.g., disposeBlinkMemory & collectGarabge.

 {
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
@@ -105,12 +122,10 @@ void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)
 
     V8PerIsolateData::from(isolate)->clearScriptRegexpContext();
 
-    // Task queue may contain delayed object destruction tasks.
-    // This method is called from navigation hook inside FrameLoader,
-    // so previous document is still held by the loader until the next event loop.
-    // Complete all pending tasks before proceeding to gc.
-    m_numberOfGCNeeded = 2;
-    m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
+    if (m_delayFinalGarbageCollection)
+        return;
+
+    collectFinalGarbage();
 }
 
 void WebLeakDetectorImpl::delayedGCAndReport(Timer<WebLeakDetectorImpl>*)