Zero closed ThreadCondition handles

third_party/WebKit/Source/wtf/ThreadingWin.cpp

Index: third_party/WebKit/Source/wtf/ThreadingWin.cpp
diff --git a/third_party/WebKit/Source/wtf/ThreadingWin.cpp b/third_party/WebKit/Source/wtf/ThreadingWin.cpp
index c7eeef150e6ccaac1ddea4a2f10a5699f794b893..83805e5864b1b68340887168eeffe1aa1357d26f 100644
--- a/third_party/WebKit/Source/wtf/ThreadingWin.cpp
+++ b/third_party/WebKit/Source/wtf/ThreadingWin.cpp
@@ -332,14 +332,21 @@ ThreadCondition::ThreadCondition()
             CloseHandle(m_condition.m_blockQueue);
         if (m_condition.m_unblockLock)
             CloseHandle(m_condition.m_unblockLock);
+
+        m_condition.m_blockLock = nullptr;
+        m_condition.m_blockQueue = nullptr;
+        m_condition.m_unblockLock = nullptr;
     }
 }
 
 ThreadCondition::~ThreadCondition()
 {
-    CloseHandle(m_condition.m_blockLock);
-    CloseHandle(m_condition.m_blockQueue);
-    CloseHandle(m_condition.m_unblockLock);
+    if (m_condition.m_blockLock)
+        CloseHandle(m_condition.m_blockLock);
+    if (m_condition.m_blockQueue)
+        CloseHandle(m_condition.m_blockQueue);
+    if (m_condition.m_unblockLock)
+        CloseHandle(m_condition.m_unblockLock);
 }
 
 void ThreadCondition::wait(MutexBase& mutex)