Oilpan: complete current sweep before preparing for new GC.

Source/platform/heap/ThreadState.cpp

Index: Source/platform/heap/ThreadState.cpp
diff --git a/Source/platform/heap/ThreadState.cpp b/Source/platform/heap/ThreadState.cpp
index c47c92bac6ba45ffcd42d4f139cde1877a0bc354..16ec9a806dbf3f4c8b9e73358da7c8524db41f2c 100644
--- a/Source/platform/heap/ThreadState.cpp
+++ b/Source/platform/heap/ThreadState.cpp
@@ -738,7 +738,6 @@ void ThreadState::setGCState(GCState gcState)
     case StoppingOtherThreads:
         checkThread();
         VERIFY_STATE_TRANSITION(m_gcState == NoGCScheduled || m_gcState == IdleGCScheduled || m_gcState == PreciseGCScheduled || m_gcState == FullGCScheduled || m_gcState == Sweeping || m_gcState == SweepingAndIdleGCScheduled || m_gcState == SweepingAndPreciseGCScheduled);

[haraken, 2015/05/21 23:01:35]

I think you can now remove a couple of states from here, since it's guaranteed
that sweeping is no progress at this point.

[sof, 2015/05/22 05:07:05]

Maybe, not so sure -- sweeping might be forbidden when collectGarbage() is
called.

[haraken, 2015/05/22 05:13:05]

Since you're calling completeSweep() before setting the StoppingOtherThreads
state, I think we can remove Sweeping, SweepingAndIdleGCScheduled and
SweepingAndPreciseGCScheduled.

Instead you can add ASSERT(!isSweepInProgress()).

-        completeSweep();
         break;
     case GCRunning:
         ASSERT(!isInGC());