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 {
@@ skipping 70 matching lines @@
 void WebLeakDetectorImpl::delayedGCAndReport(Timer<WebLeakDetectorImpl>*)
 {
     // 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.
 
     // Inspect counters on the next event loop.
-    if (--m_numberOfGCNeeded)
+    if (--m_numberOfGCNeeded > 0) {
         m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
-    else
+    } else if (m_numberOfGCNeeded > -1 && InProcessWorkerMessagingProxy::proxyCount()) {
+        // It is possible that all posted tasks for finalizing in-process proxy objects
+        // will not have run before the final round of GCs started. If so, do yet
+        // another pass, letting these tasks run and then afterwards perform a GC to tidy up.
+        //
+        // TODO(sof): use proxyCount() to always decide if another GC needs to be scheduled.
+        // Some debug bots running browser unit tests disagree (crbug.com/616714)
+        m_delayedGCAndReportTimer.startOneShot(0, BLINK_FROM_HERE);
+    } 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