Print additional message for RELEASE_ASSERT in builds used for fuzzing.

third_party/WebKit/Source/wtf/Assertions.h

Index: third_party/WebKit/Source/wtf/Assertions.h
diff --git a/third_party/WebKit/Source/wtf/Assertions.h b/third_party/WebKit/Source/wtf/Assertions.h
index cab1dbc9709871de7d002f77f111a8cf81e46cd8..5b6f46e09cf749fa1e782c1cd0420ec6d03fe40a 100644
--- a/third_party/WebKit/Source/wtf/Assertions.h
+++ b/third_party/WebKit/Source/wtf/Assertions.h
@@ -289,11 +289,19 @@ private:
       http://code.google.com/p/chromium/issues/entry?template=Security%20Bug
 */
 // RELEASE_ASSERT is deprecated.  We should use CHECK() instead.
+#if defined(ADDRESS_SANITIZER)

[inferno, 2016/08/12 17:43:56]

This should come after #if ENABLE(ASSERT) block in an #elif (don't need an outer
#if #endif. For debug builds, we don't want to change behavior.

+#define RELEASE_ASSERT_FOR_FUZZING() do { \
+    WTFLogAlways("RELEASE_ASSERT failed.\n"); \

[inferno, 2016/08/12 17:43:56]

We would need to get condition failed and stacktrace. can you check if
"LOG_IF(FATAL, !(condition)) << "Release assert failed: " #condition ". "" code
does it. See also line 264 where it is used.

+    IMMEDIATE_CRASH(); \
+} while (0)
+#define RELEASE_ASSERT(assertion) (UNLIKELY(!(assertion)) ? (RELEASE_ASSERT_FOR_FUZZING()) : (void)0)
+#else // defined(ADDRESS_SANITIZER)
 #if ENABLE(ASSERT)
 #define RELEASE_ASSERT(assertion) ASSERT(assertion)
 #else
 #define RELEASE_ASSERT(assertion) (UNLIKELY(!(assertion)) ? (IMMEDIATE_CRASH()) : (void)0)
 #endif
+#endif // defined(ADDRESS_SANITIZER)
 // TODO(tkent): Move this to base/logging.h?
 #define RELEASE_NOTREACHED() LOG(FATAL)