Revert of Delay leak reporting until worker in-process proxies have been finalized.

third_party/WebKit/Source/web/WebLeakDetector.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "public/web/WebLeakDetector.h"
 
 #include "bindings/core/v8/V8GCController.h"
 #include "core/editing/spellcheck/SpellChecker.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/inspector/InstanceCounters.h"
-#include "core/workers/InProcessWorkerMessagingProxy.h"
 #include "core/workers/WorkerThread.h"
 #include "platform/Timer.h"
 #include "public/web/WebFrame.h"
 #include "web/WebLocalFrameImpl.h"
 
 namespace blink {
 
 namespace {
 
 class WebLeakDetectorImpl final : public WebLeakDetector {
 WTF_MAKE_NONCOPYABLE(WebLeakDetectorImpl);
 public:
     explicit WebLeakDetectorImpl(WebLeakDetectorClient* client)
         : m_client(client)
         , m_delayedGCAndReportTimer(this, &WebLeakDetectorImpl::delayedGCAndReport)
         , m_delayedReportTimer(this, &WebLeakDetectorImpl::delayedReport)
-        , m_numberOfWorkerGCs(0)
+        , m_numberOfGCNeeded(0)
     {
         DCHECK(m_client);
     }
 
     ~WebLeakDetectorImpl() override {}
 
     void prepareForLeakDetection(WebFrame*) override;
     void collectGarbageAndReport() override;
 
 private:
     void delayedGCAndReport(Timer<WebLeakDetectorImpl>*);
     void delayedReport(Timer<WebLeakDetectorImpl>*);
 
     WebLeakDetectorClient* m_client;
     Timer<WebLeakDetectorImpl> m_delayedGCAndReportTimer;
     Timer<WebLeakDetectorImpl> m_delayedReportTimer;
-    int m_numberOfWorkerGCs;
+    int m_numberOfGCNeeded;
 };
 
 void WebLeakDetectorImpl::prepareForLeakDetection(WebFrame* frame)
 {
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     v8::HandleScope handleScope(isolate);
 
     // For example, calling isValidEmailAddress in EmailInputType.cpp with a
     // non-empty string creates a static ScriptRegexp value which holds a
     // V8PerContextData indirectly. This affects the number of V8PerContextData.
@@ skipping 22 matching lines @@
 
 void WebLeakDetectorImpl::collectGarbageAndReport()
 {
     V8GCController::collectAllGarbageForTesting(V8PerIsolateData::mainThreadIsolate());
     // Note: Oilpan precise GC is scheduled at the end of the event loop.
 
     // 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_numberOfWorkerGCs = 0;
+    m_numberOfGCNeeded = 2;
     m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
 }
 
 void WebLeakDetectorImpl::delayedGCAndReport(Timer<WebLeakDetectorImpl>*)
 {
-    // The initial GC will have swept out Resource objects, but their finalizers
-    // will let go of yet more objects, needing another GC after having been back
-    // to the event loop to run any clean-up tasks.
+    // We do a second and third GC here to address flakiness
+    // The second GC is necessary as Resource GC may have postponed clean-up tasks to next event loop.
+    // The third GC is necessary for cleaning up Document after worker object died.
+
     V8GCController::collectAllGarbageForTesting(V8PerIsolateData::mainThreadIsolate());
     // Note: Oilpan precise GC is scheduled at the end of the event loop.
 
-    // If there are any in-process worker proxy objects still around waiting for
-    // the worker to notify of destruction, we need to ensure that these have all
-    // been destructed and their garbage collected (as they hold a Document
-    // reference, and would generate a leak if not.)
-    //
-    // Do that by monitoring the remaining proxy count, iterating at most two times.
-    if (InProcessWorkerMessagingProxy::proxyCount() && m_numberOfWorkerGCs < 2) {
-        m_numberOfWorkerGCs++;
+    // Inspect counters on the next event loop.
+    if (--m_numberOfGCNeeded)
         m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
-    } else {
+    else
         m_delayedReportTimer.startOneShot(0, BLINK_FROM_HERE);
-    }
 }
 
 void WebLeakDetectorImpl::delayedReport(Timer<WebLeakDetectorImpl>*)
 {
     DCHECK(m_client);
 
     WebLeakDetectorClient::Result result;
     result.numberOfLiveAudioNodes = InstanceCounters::counterValue(InstanceCounters::AudioHandlerCounter);
     result.numberOfLiveDocuments = InstanceCounters::counterValue(InstanceCounters::DocumentCounter);
     result.numberOfLiveNodes = InstanceCounters::counterValue(InstanceCounters::NodeCounter);
@@ skipping 12 matching lines @@
 }
 
 } // namespace
 
 WebLeakDetector* WebLeakDetector::create(WebLeakDetectorClient* client)
 {
     return new WebLeakDetectorImpl(client);
 }
 
 } // namespace blink