Oilpan: Decommit backing storage of CallbackStacks

third_party/WebKit/Source/platform/heap/ThreadState.cpp

Index: third_party/WebKit/Source/platform/heap/ThreadState.cpp
diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.cpp b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
index 3d4af7efb9837365ec08897f5d8e4fceba6f3272..99e07cd7e454635e650444513d978a5b5d99e6fd 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.cpp
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
@@ -485,6 +485,8 @@ void ThreadState::threadLocalWeakProcessing()
     // Perform thread-specific weak processing.
     while (popAndInvokeThreadLocalWeakCallback(visitorScope.visitor())) { }
 
+    m_threadLocalWeakCallbackStack->decommit();
+
     if (isMainThread()) {
         double timeForThreadLocalWeakProcessing = WTF::currentTimeMS() - startTime;
         DEFINE_STATIC_LOCAL(CustomCountHistogram, timeForWeakHistogram, ("BlinkGC.timeForThreadLocalWeakProcessing", 1, 10 * 1000, 50));