Diagnose failing GC transition on forced Oilpan GC.

third_party/WebKit/Source/bindings/core/v8/V8GCController.cpp

 /*
  * Copyright (C) 2009 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 364 matching lines @@
         //       some heap allocated objects own objects that contain persistent handles
         //       pointing to other heap allocated objects. To break the chain, we need multiple GCs.
         //
         // Regarding (1), we force a precise GC at the end of the current event loop. So if you want
         // to collect all garbage, you need to wait until the next event loop.
         // Regarding (2), it would be OK in practice to trigger only one GC per gcEpilogue, because
         // GCController.collectAll() forces 7 V8's GC.
         Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithSweep, BlinkGC::ForcedGC);
 
         // Forces a precise GC at the end of the current event loop.
-        if (ThreadState::current())
+        if (ThreadState::current()) {
+            // Temporary asserts to diagnose crbug.com/571207's failure to transition
+            // to FullGCScheduled.
+            RELEASE_ASSERT(!ThreadState::current()->isSweepingInProgress());
+            RELEASE_ASSERT(!ThreadState::current()->isInGC());
             ThreadState::current()->setGCState(ThreadState::FullGCScheduled);
+        }
     }
 
     TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "UpdateCounters", TRACE_EVENT_SCOPE_THREAD, "data", InspectorUpdateCountersEvent::data());
 }
 
 void V8GCController::collectGarbage(v8::Isolate* isolate)
 {
     v8::HandleScope handleScope(isolate);
     RefPtr<ScriptState> scriptState = ScriptState::create(v8::Context::New(isolate), DOMWrapperWorld::create(isolate));
     ScriptState::Scope scope(scriptState.get());
@@ skipping 48 matching lines @@
     Visitor* m_visitor;
 };
 
 void V8GCController::traceDOMWrappers(v8::Isolate* isolate, Visitor* visitor)
 {
     DOMWrapperTracer tracer(visitor);
     isolate->VisitHandlesWithClassIds(&tracer);
 }
 
 } // namespace blink