Add UseCounter for decimal with leading zero.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 9a881f2383ce6e6107c7c3da77f234113e62749f..a338dab1db00564789e966f2b637db2c8560e547 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -5609,9 +5609,10 @@ class V8_EXPORT Isolate {
     kLegacyFunctionDeclaration = 29,
     kRegExpPrototypeSourceGetter = 30,
     kRegExpPrototypeOldFlagGetter = 31,
+    kDecimalWithLeadingZeroInStrictMode = 32,
 
-    // If you add new values here, you'll also need to update V8Initializer.cpp
-    // in Chromium.
+    // If you add new values here, you'll also need to update Chromium's:
+    // UseCounter.h, V8PerIsolateData.cpp, histograms.xml
     kUseCounterFeatureCount  // This enum value must be last.
   };