diff --git a/webrtc/base/criticalsection.h b/webrtc/base/criticalsection.h
index db197d2e0..0b4bb1505 100644
--- a/webrtc/base/criticalsection.h
+++ b/webrtc/base/criticalsection.h
@@ -27,9 +27,9 @@
 #include <pthread.h>
 #endif
 
-#ifdef _DEBUG
+#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
 #define CS_TRACK_OWNER 1
-#endif  // _DEBUG
+#endif
 
 #if CS_TRACK_OWNER
 #define TRACK_OWNER(x) x
@@ -58,6 +58,8 @@ class LOCKABLE CriticalSection {
   bool CurrentThreadIsOwner() const {
     return crit_.OwningThread == reinterpret_cast<HANDLE>(GetCurrentThreadId());
   }
+  // Use only for DCHECKing.
+  bool IsLocked() { return crit_.LockCount != -1; }
 
  private:
   CRITICAL_SECTION crit_;
@@ -102,6 +104,10 @@ class LOCKABLE CriticalSection {
     return true;
 #endif  // CS_TRACK_OWNER
   }
+  // Use only for DCHECKing.
+#if CS_TRACK_OWNER
+  bool IsLocked() { return thread_ != 0; }
+#endif
 
  private:
   pthread_mutex_t mutex_;
diff --git a/webrtc/base/criticalsection_unittest.cc b/webrtc/base/criticalsection_unittest.cc
index 6f3c7e931..ff4fdef94 100644
--- a/webrtc/base/criticalsection_unittest.cc
+++ b/webrtc/base/criticalsection_unittest.cc
@@ -281,4 +281,21 @@ TEST(CriticalSectionTest, Basic) {
   EXPECT_EQ(0, runner.shared_value());
 }
 
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+TEST(CriticalSectionTest, IsLocked) {
+  // Simple single-threaded test of IsLocked.
+  CriticalSection cs;
+  EXPECT_FALSE(cs.IsLocked());
+  cs.Enter();
+  EXPECT_TRUE(cs.IsLocked());
+  cs.Leave();
+  EXPECT_FALSE(cs.IsLocked());
+  if (!cs.TryEnter())
+    FAIL();
+  EXPECT_TRUE(cs.IsLocked());
+  cs.Leave();
+  EXPECT_FALSE(cs.IsLocked());
+}
+#endif
+
 }  // namespace rtc