Allow assertions to be enabled in Blink Release builds.

Source/wtf/Assertions.h

Index: Source/wtf/Assertions.h
diff --git a/Source/wtf/Assertions.h b/Source/wtf/Assertions.h
index d4b281ab636389883abad7ea34a03b0551f35bbe..04eaa6e657b2c4e204f1290604c66442df8326b6 100644
--- a/Source/wtf/Assertions.h
+++ b/Source/wtf/Assertions.h
@@ -43,22 +43,19 @@
 #include "wtf/Compiler.h"
 #include "wtf/WTFExport.h"
 
+// Users must test "#if ENABLE(ASSERT)", which helps ensure that code
+// testing this macro has included this header.
+#ifndef ENABLE_ASSERT
 #ifdef NDEBUG
-/* Disable ASSERT* macros in release mode. */
-#define ASSERTIONS_DISABLED_DEFAULT 1
+/* Disable ASSERT* macros in release mode by default. */
+#define ENABLE_ASSERT 0
 #else
-#define ASSERTIONS_DISABLED_DEFAULT 0
+#define ENABLE_ASSERT 1
+#endif /* NDEBUG */
 #endif
 
 #ifndef BACKTRACE_DISABLED
-#define BACKTRACE_DISABLED ASSERTIONS_DISABLED_DEFAULT
-#endif
-
-// Users must test "#if ENABLE(ASSERT)", which helps ensure that code
-// testing this macro has included this header.
-#ifndef ENABLE_ASSERT
-// Notice the not below:
-#define ENABLE_ASSERT !ASSERTIONS_DISABLED_DEFAULT
+#define BACKTRACE_DISABLED !ENABLE(ASSERT)
 #endif
 
 #ifndef ASSERT_MSG_DISABLED